sofia and her brother combined to read a total of 40 books over the summer sofia read four times as many books as her brother how many books did each person read

Answers

Answer 1

The number of books that Sofia read is 32 books and the brother read 8 books.

How to calculate the number of books read?

An equation simply has to do with the statement that illustrates the variables given. In this case, it is vital to note that two or more components are considered in order to be able to describe the scenario.

From the information, Sofia and her brother combined to read a total of 40 books over the summer sofia read four times as many books as her brother how many books did each person read

Let the number of books read by the brother = x

Number of books read by Sofia = 4x

Therefore, x + 4x = 40

5x = 40.

Divide

x = 40 / 5

x = 8

The brother read 8 books

Sofia read = 4x

= 4 × 8

= 32 books.

Learn more about equations on:

https://brainly.com/question/2972832

#SPJ1


Related Questions

the cube root parent function is reflected and stretched by four. it is translated six to the right and five down. write an equation that represents this new function

Answers

The equation for new function is,

⇒ f (x) = ∛( 1/4x - 6) - 5

What is Function?

A relation between a set of inputs having one output each is called a function.

Given that;

The parent function is,

⇒ g (x) = ∛x

Now, After  reflected and stretched by 4, we get;

⇒ g (x) = f (1/4x) = ∛ 1/4x

And, After translated 6 units to the right, we get;

⇒ g (x) = f (x - 6) = ∛ 1/4x - 6

And, After 5 unit down, we get;

⇒ g (x) = h (x) - 5 = ∛( 1/4x - 6) - 5

Learn more about the function visit:

https://brainly.com/question/28793267

#SPJ2

write an equation that expresses the following relationship p varies derectly with d and inversly with the square of u. In your equation use k as the proportionality

Answers

P= kd/u^2 is the equation which expresses the following relationship p varies derectly with d and inversly with the square of u.

What is Equation?

Equation is a mathematical statement that expresses the equality of two expressions. An equation is written as an expression containing an equal sign, with each side of the equal sign representing a mathematical expression. The purpose of an equation is to show the relationship between two or more variables, such as a change in one variable resulting in a change in another. Equations are used to solve problems in mathematics, physics, economics, and many other fields.

The equation states that p is directly proportional to d, and inversely proportional to u squared. This means that as d increases, p increases, and as u increases, p decreases. The constant of proportionality, k, is a measure of the strength of the relationship between p, d, and u.

To know more about Equation click-
https://brainly.com/question/2972832
#SPJ4

Solve the inequality. Graph the solution.
-1/3h > or equal to 8
(step by step equation)

Answers

We can solve the inequality to get:

h ≤ -3

And its graph can be seen below.

How to solve the inequality?

Here we have the following inequality:

-(1/3)*h ≥ 8

To solve the inequality, we need to isolate h.

So we can multiply both sides by -3 (notice that this will change the sign of the inequality symbol)

So we will get:

-3*(-1/3)*h ≤ -3*h

h ≤ -3

Now to graph this, we need to draw a closed circle at -3, and draw an arrow that gose to the left.

Laern more about inequalities:

https://brainly.com/question/24372553

#SPJ1

On may 4th, an investor writes one s&p 100 jan 185 put at 6. His maximum potential gain on this position is:

Answers

An investor writes a s&p 100 Jan. 185 put at $6 on May 4. In this situation, his function maximum potential benefit is $600.

Define function.

We could create a function with a codomain of sets of numbers and X being the set of individuals once more. For instance, create the function c so that its output c(x) is the number of offspring of each person x for which the codomain Y is the set of whole numbers.

what is benefit?

A benefit is a positive outcome or advantage that results from something. It can refer to the positive aspects or advantages of a product, service, or action, and can be tangible or intangible. Benefits can include increased efficiency, cost savings, improved safety, increased customer satisfaction, and many other positive outcomes.

Here,

As a put buyer, the most you may lose is the premium you previously paid to purchase the put option.

The option price must be reduced to equal the strike price less any already-paid premium in order to break even.

The strike price less the premium is your maximum gain as a put buyer. The most bullish option strategy is thought to be purchasing call options.

This tactic allows the buyer of the call option the choice, but not the responsibility, to purchase the stock at a certain price at a precise moment.

Whenever the price of the security increases using this approach, the buyer benefits. A long position is one in which a call or put option is purchased or held.

Investors have the option of purchasing from or selling to the other investor at a predetermined price.

On the other hand, a short position is when you sell a call or put option. Writers must purchase from people holding long positions or buying options.

To know more about function visit:

brainly.com/question/28193995

#SPJ4

On May 4th an investor writes on s&p 100 Jan 185 put at $6. his function maximum potential gain in this position is $600.

Define function.

We could create a function with a codomain of sets of numbers and X being the set of individuals once more. For instance, create the function c so that its output c(x) is the number of offspring of each person x for which the codomain Y is the set of whole numbers.

Your maximum loss as a put buyer is the premium already paid to buy the put option. To break even the option price must be lowered to cover the strike price minus the premium already paid. Your maximum profit as a put buyer is the strike price minus the premium. Buying call options are considered the most bullish options strategy.

This strategy gives the call option buyer the right but no obligation to buy the security at a specific price at a specific time. With this strategy, the buyer benefits when the price of the security rises. Buying or holding a call or put option is a long position. Investors have the right to buy or sell to the writing investor at a specified price. Conversely selling or selling a call or put option is a short position. Writers must buy or sell from long position holders or option buyers.

To learn more about an investor visit:-

brainly.com/question/28175452

#SPJ4

the perimeter of the trapezoid is 18x +18 find the missing length of the lower base
PLEASE HURRY

Answers

Answer:

Step-by-step explanation:

8x+18=2x+x+4x-3

8x+18=7x-3

perimeter = x+21

How do you check if a function has an inverse function?

Answers

We can check if a function has an inverse function using horizontal  Line Test.

What is Function?

A relation between a collection of inputs and outputs is known as a function. In plain English, a function is an association between inputs in which each input is connect

horizontal  Line Test

Make f a function. Any horizontal line that crosses the f graph more than once indicates that f lacks an inverse. F does have an inverse if there are no horizontal lines that cross the graph of f more than once.

To Learn more about function from the link:

https://brainly.com/question/10439235

#SPJ4

What is the value of x in the equation 2.5 6x 4 )= 10 4 1.5 0.5 x?

Answers

The value of x in this problem is 2.

Our given algebraic equation is 2.5 ( 6x - 4 ) = 10 + 4 ( 1.5 + 0.5x) and in this, we have to find the final value of x.

Use the transposing method to isolate the variable x and then solve for it.

distribute brackets on both sides of the equation.

= 2.5*6x - 2.5*4 = 10 + 4*1.5 + 4*0.5x

= 15x - 10 = 10 + 6 + 2x

collect terms in x to the left side and numeric values to the right side.

= 15x - 2x = 10 + 6 + 10

= 13x = 26

= x = 26/13 = 2

Therefore the final value of x in this equation will be 2.

To learn more about Algebraic Equations, visit: https://brainly.com/question/953809

#SPJ4

HELPPPPPPP MEEEEE


If a trapezoid has an area of 135cm^2 and it’s height is 10cm and one base is 12 cm, find the other base length.




thxxx <333

Answers

The length of other base  is 15 cm.

The area of a trapezoid can be found by using the formula:

Area = (b1+b2) * h / 2 where b1 and b2 are the lengths of the bases, and h is the height.

Given that the area of the trapezoid is 135 cm^2, the height is 10 cm, and one base is 12 cm, we can substitute these values into the formula to find the length of the other base.

Area = (b1+b2) * h / 2 = 135cm^2

We can solve for the other base length by isolating b1

b1 = 2*Area/h - b2

b1 = 2*135/10 - 12 = 27 - 12 = 15

So, the other base length is 15 cm.

Therefore, The length of other base  is 15 cm.

To learn more about trapezoid,

Visit; brainly.com/question/8643562

#SPJ4

A juice container advertises it now contains 20% more juice. Originally, it had 27.5 ounces, how
much juice does it now contain?

Answers

Answer:

33 ounces

Explanation:

20% of 27.5 ounces is 5.5 ounces.

To find how much more juice the container has, we add 5.5 to 27.5, which equals to 33 ounces

I would like help with this, please. Someone give me an answer in the next day or two.

Answers

Answer:

one solution

Step-by-step explanation:

The two lines cross at exactly one point.  That means there is one solution.

How the Earth rotates around the sun and moon?

Answers

The Earth orbits the Sun and rotates around its own axis. The Moon orbits the Earth and is held in place by the Earth’s gravity. This is why the length of a day is gradually increasing over time.

The Moon’s gravitational pull causes the tides, which is why the ocean’s water level rises and falls. The gravitational pull of the Moon also affects the Earth’s rotation by slowing it down slightly. This is why the length of a day is gradually increasing over time.

The Earth orbits the Sun and rotates around its own axis, while the Moon orbits the Earth and is held in place by the Earth’s gravity. The Moon’s gravitational pull causes the tides and affects the Earth’s rotation by slowing it down slightly, resulting in a gradual increase in the length of a day.

Learn more about length here

https://brainly.com/question/13194650

#SPJ4

answer quick its due in ten minutes

Answers

The number of grams of sugar that would be in a 200 ml glass of juice, given the carton, is 13. 2 grams of sugar

How to find the number of grams of sugar ?

In a 250 ml glass of juice, we would see 16. 5 g of sugar. Given this information, we can find the amount of sugar in a 200 ml of juice by using direct proportion.

The amount of sugar in 200 ml of juice is :

= ( Amount of sugar in 250 ml x Quantity of juice ) / Quantity of base quantity of juice

= ( 16. 5 x 200 ) / 250

= 3, 300 / 250

= 13. 2 grams of sugar

Find out more on grams of sugar at https://brainly.com/question/8611897

#SPJ1

Write an exponential function to describe the given sequence of numbers,

10, 60, 360, 2160, 12960,.

Answers

The exponential function to describe the given sequence of numbers, 10, 60, 360, 2160, 12960, ... is aₙ = 10 × [tex]6^{n-1}[/tex].

The given series 10, 60, 360, 2160, 12960, ... is a geometric progression.

a = 10

The common difference r = 60/10 = 6

As we know the general formula of the nth term of a geometric series is

aₙ = a × [tex]r^{n-1}[/tex]

Now, put the values of a = 10, r = 6 and n in the general formula,

aₙ = 10 × [tex]6^{n-1}[/tex]

Therefore, the required exponential function to describe the given sequence of numbers, 10, 60, 360, 2160, 12960, ... is aₙ = 10 × [tex]6^{n-1}[/tex].

To know more about geometric series, here

https://brainly.com/question/4617980

#SPJ4

Geometry: Applications of All Right Triangles
Look at the attachments below to answer this question.

Answers

Given:

A length of a side of an equilateral triangle = 32 cm

Formula Used:

If in an equilateral triangle with side length 'a' then,

Area of an equilateral triangle = [(√3)/4] × a2 

Calculations:

Area of an equilateral triangle = [(√3)/4] × 322

⇒ (1024 × √3)/4

⇒ 256√3 cm2

I don't know help! image of the question is below

Answers

The value of x from the given triangle is 7√2 units.

What are trigonometric ratios?

The sides and angles of a right-angled triangle are dealt with in Trigonometry. The ratios of acute angles are called trigonometric ratios of angles. The six trigonometric ratios are sine (sin), cosine (cos), tangent (tan), cotangent (cot), cosecant (cosec), and secant (sec).

From the given triangle, one of the angle in right angle triangle is 45°, opposite side is 7 units and hypotenuse is x units.

We know that, sinθ =Opposite/Hypotenuse

sin45°=7/x

1/√2=7/x

x=7√2 units

Therefore, the value of x is 7√2 units.

Learn more about the trigonometric ratios here:

brainly.com/question/25122825.

#SPJ1

Find the measure of MN

Answers

Answer:

60 degrees

Step-by-step explanation:

The total measure of a circle is 360 degrees.

360-140-100 = 120

Angles MON and NOP are equivalent which makes MN and NP equivalent.

120/2 = 60 degrees = MN

Bart and April are purchasing a house with a 15-year, 2/1 ARM for $315,000 at 5. 85% with a 2/8 cap structure. What will the difference in

payments be from year 2 to year 3?


$309. 69

$595. 18

$333. 68

$86. 56

Answers

The monthly payment for this difference would be $1,361.21. An Adjustable Rate Mortgage (ARM) is a type of mortgage in which the interest rate on the loan changes over time.

An Adjustable Rate Mortgage (ARM) payment is based on various factors such as the loan amount, interest rate, and the terms of the ARM. The interest rate is usually tied to a specific financial index, such as the U.S.

Here is the calculation format for the difference in payments between year 2 and year 3 for Bart and April's mortgage:

Total amount to be paid for the mortgage: $315,000

Rate of interest: 5.85% (Depreciating rate)

Time = 2 years:

a. Remaining amount to be paid after 2 years:

Principal × (1 - Rate/100)^time

= $315,000 × (1 - 5.85/100)²

= $315,000 × (1 - 0.0585)²

= $279,223.01

Time = 3 years:

a. Remaining amount to be paid after 3 years:

Principal × (1 - Rate/100)^time

= $315,000 × (1 - 5.85/100)³

= $315,000 × (1 - 0.0585)³

= $262,888.46

Difference in payments from year 2 to year 3:

= Remaining amount after 2 years - Remaining amount after 3 years

= $279,223.01 - $262,888.46

= $16,334.55

The monthly payment for this difference would be $1,361.21, which is calculated by dividing the difference in payments by 12:

$16334.546/12 = $1361.21

Learn more about ARM, here https://brainly.com/question/30127827

#SPJ4

Which bag of potatoes is the better deal?

Answers

Answer:

5 kg.

Step-by-step explanation:

2 kg for $0.96 is more expensive than 5 kg for $1.95

Ryan has a points card for a movie theater. He receives 85 rewards points just for signing up. He earns 7.5 points for each visit to the movie theater. He needs 160 points for a free movie ticket. Write and solve an equation which can be used to determine vv, the number of visits Ryan must make to earn a free movie ticket.

Answers

Answer:

85+7.5v=160

7.5v=160-85

7.5v=75

V=75/7.5

V=10

Ryan would need to take 10 visits to get a free ticket.

How does Earth's rotation cause day and night ?

Answers

Earth's rotation is what causes day and night. As Earth rotates on its axis, half of the planet is facing the Sun, while the other half is facing away from the Sun.

The half of the planet facing the Sun experiences daylight, while the half facing away from the Sun experiences darkness. This cycle repeats itself every 24 hours, resulting in the day and night cycle that we experience.

Earth's rotation causes day and night by rotating on its axis, with half of the planet facing the Sun and the other half facing away from the Sun. This cycle of daylight and darkness lasts for  creating the day and night cycle that we observe.Earth's rotation is what causes day and night. As Earth rotates on its axis, half of the planet is facing the Sun, while the other half is facing away from the Sun.

learn more about axis here

https://brainly.com/question/2491015

#SPJ4

Can you pls help me with this

Answers

Answer:

y = x - 2

Step-by-step explanation:

Slope intercept form of an equation: y =mx +b

Here m is the slope and b is the y-intercept.

Choose any two points on the line.            

 (2,0)  ; (0,-2)

Now, find the slope.

        [tex]\sf \boxed{Slope = \dfrac{y_2-y_1}{x_2-x_1}}[/tex]

                   [tex]= \dfrac{-2 - 0}{0 - 2}\\\\=\dfrac{-2}{-2}\\\\= +1[/tex]

m = 1.

Now, y = 1x +  b

The (2 , 0) passes through the line. Substitute x = 2 and y = 0 in the above equation and find the value of 'b'.

       0 = 1*2 + b

       0 =  2 + b

        -2 = b

Equation of line:

              y = x - 2

A rectangle has a perimeter represented by the expression 4x−8. Which expression also represents this perimeter? 4(x-8), 2(2x-8), 2(2x-4), 4(2x-4)

Answers

The perimeter expression of a rectangle has a perimeter represented by the expression 4x−8 is 2(2x - 4)

How to determine the perimeter expression

From the question, we have the following parameters that can be used in our computation:

Perimeter = 4x - 8

Factor out 2 from the expression

So, we have the following representation

Perimeter = 2 * 2x - 2 * 4

So, we have

Perimeter = 2(2x - 4)

Hence, the perimeter is 2(2x - 4)

Read more about perimeter at

https://brainly.com/question/17297081

#SPJ1

A triangle ha two ide of length 7 and 17. What i the mallet poible whole-number length for the third ide?

Answers

According to triangle inequality theorem a triangle with two sides 7 units and 17 units, has a third side which measures 10 units.

What is Triangle Inequality Theorem?

According to triangle inequality theorem, the sum of the lengths of any two sides of a triangle is greater than the length of the third side.

The two sides of a triangle are -

a=7, b=x and c=17, where a, b and c are the sides of the triangle.

As, 17 is a bigger number so let it be the biggest side.

Now, according to triangle inequality theorem -

a + b = c

7 + x = 17

x = 17 -7

x = 10

Therefore, the third side of the triangle measures 10 units.

To learn more about triangle inequality theorem from the given link

https://brainly.com/question/309896

#SPJ4

Find the output (y) of the function y= -7+5 if the input is (x) is 15

Y=

Answers

Answer:  -100

Step-by-step explanation:   -7(15)+5

It said x=15 so put 15 in and solve from there and that would be -100

HOPE THIS HELPS ANY I JUST completed FUNCTIONS AND MAN IT WAS FUN

A conical paper cup is 10 cm tall with a radius of 7 cm. The cup is being filled with water so that the water level rises at a rate of 3 cm/sec. At what rate is water being poured into the cup when the water level is 9 cm

Answers

The rate exists water being poured into the cup when the water level is 9 cm exists [tex]$$1458 \pi \mathrm{cm}^3 s^{-1}$$[/tex].

What is meant by chain rule?

To determine the derivative of a composite function in differential calculus, apply the chain rule formula. If y = f(g(x)), then according to the chain rule, the instantaneous rates of change of the functions f and g with respect to x produce the instantaneous rate of change of f with respect to x.

A composition of functions, such as the composition of the functions f and g, f(g(x)), can be used to determine the derivative using the chain rule.

Let us set up the following variables:

R, Radius of conical cup (cm) = 30 cm

H, Height of the conical cup (cm) = 10 cm

Our aim is to find dV/dt when h = 9 and we are given dh/dt = 2

By similar triangles we have

r : h = R : H

r/h = 30/10

⇒ r = 3h

The volume of a cone is 1/3π r²h, So:

V = 1/3π r²h

simplifying the equation, we get

= 1/3π (3h²)h

= 1/3π 9h²h

= 3π h³

Differentiating wrt h we get:

dV/dh = 9π h²

Applying the chain rule we have:

dV/dt = (dV/dh)(dh/dt)

= 9π h² × 2

= 18π h²

If h = 9 then

[tex]$\left[\frac{d V}{d t}\right]_{h=9}=18 \pi\left(9^2\right)=1458 \pi \mathrm{cm}^3 s^{-1}$$[/tex].

Therefore, the rate exists water being poured into the cup when the water level 9 cm exists [tex]$$1458 \pi \mathrm{cm}^3 s^{-1}$$[/tex].

To learn more about chain rule refer to:

https://brainly.com/question/11549233

#SPJ4

Write the coordinates of the vertices after a rotation 90 degrees counterclockwise around the origin.

Answers

Answer: J' (8, -9); K' (8, -2); L' (3, -2); M' (3, -9)

Step-by-step explanation:

A rotation of 90 degrees counterclockwise is (x, y) -> (-y, x), so

J (-9, -8) -> J' (8, -9)

First, you take negative 8 (y) of J and make it positive 8 for the x of J'. Then, take -9 (y) of J and switch it to x of J'.

You repeat this process for the rest of the points. X switches to Y with the opposite sign and Y switches to X but stays the same.

K (-2, -8) -> K' (8, -2)

L (-2, -3) -> (3, -2)

M (-9, -3) -> (3, -9)

How do you find the legs of a 45 45 90 triangle given the hypotenuse?

Answers

The value of the legs of the triangle would be hypotenuse/√2.

You can use basic trigonometry to solve this problem. We know that the sine of the angle made by the hypotenuse and the base is equal to the ratio of perpendicular height and the hypotenuse, given that the angle is 45° the perpendicular will be equal to ⇒ hypotenuse × sin(45°).

That is perpendicular=hypotenuse/√2

Similarly, the cosine of the angle made by the hypotenuse and the base is equal to the ratio of base length and the hypotenuse, given that the angle is 45° the base will be equal to ⇒ hypotenuse × cos(45°)

That is base=hypotenuse/√2

Therefore, the value of the legs of the 45°-45°-90° triangle would be hypotenuse/√2.

Learn more about Trigonometry on

https://brainly.com/question/29002217?referrer=searchResults

#SPJ4

If 16 inches of ribbon costs $2.08, how much will 36 inches of
ribbon cost? Show your thinking.

Answers

4.68

find unit rate by dividing 208 cents by 16 which is 13 than multiply by 36

Answer:

16 inches of ribbon cost- $2.08

36 inches of ribbon cost- ?

36*$2.08/ 16

$74.88/16

= $4.68

Thus, 36 inches of ribbon would cost $4.68

BUILD PERSEVERANCE Part A Simplify the expression. (8x + 6) + (5 − x) − 2 (3x+1) ​

Answers

The expression is x + 9.Generally speaking, an expression is at its simplest form when it is most usable.

What is its most basic form?Generally speaking, an expression is at its simplest form when it is most usable. as in this: 5x + x 3.To simplify an expression, create a similar expression devoid of any identical terms. Therefore, we shall rephrase the expression using the fewest number of terms possible.Determine the domain before you can simplify a rational expression.The collection of all possible inputs to a function, including all potential values for the variables, that enable the function to function.

Explanation:

8x + 6+5 - x - 6x - 2

= x + 9.

To learn more about expression refer to:

https://brainly.com/question/723406

#SPJ1

What is the inverse of the inverse of P → Q?

Answers

The inverse of ∼P→∼Q is P->Q.

Given ∼P→∼Q

Its inverse, ∼(∼P)→∼(∼Q), means that P→Q.

If the hypothesis is correct but the conclusion is untrue, a conditional statement is false. If the statement in the example above read, "If you achieve good marks then you will not get into a good college," it would be untrue. A conditional statement that has been modified or rearranged is referred to as a related conditional. An if-then statement, also known as a conditional statement, is a set of hypotheses followed by a conclusion. It is noted that p→q. Read this: if p, then q.

To learn more about inverse here:

https://brainly.com/question/2541698

#SPJ4

Other Questions
Keshia goes to the post office to mail a package and a few letters. Stamps cost 49 cents each. It will cost $7.65 to mail the package. Keshila has 10.00. a. Write an inequality to represent this situation, where x is the number of stamps. ALGEBRA 2 NEED HELP ASAP What are 4 examples of variable expenses? Where is Hamilton writing from? State how Moses used his freedom in accordance to god's plan and will whats the answer? please help! Which of the following is not true about cluster sampling?Cluster sampling has the advantage of reducing sampling variability.Cluster sampling has the advantage of saving time and money.Cluster sampling uses clusters, which are miniature, nonoverlapping versions of the population.Cluster sampling uses randomly selected clusters and samples everyone within each cluster. answer is A How many nine-digit numbers can be made using each of the digits 1 through 9 exactly once with the digits alternating between odd and even What is the coefficient of XY in 7xy? A field is in the shape of a square. The length of the field is 5xy. What is the area of the field in terms of x and y? Write the variables inalphabetical order. I really dont know and Im desperate :( A pool is being drained by a pump at a rate of 4 gallons per minute. An identical pump is added to help drain the pool. How does the second pump affect the rate of drainage? Explain. Meg Whitman, former CEO of HP, stated that early in her career she gained credibility and displayed competence through her focus on Multiple choice question. creating a successful track record. giving great presentations. giving many large gifts. keeping conversations short. The United Statesgovernment passed theDawes Act in 1887 with thepurpose:A. to naturalize all remaining NativeAmericans in the West.B. to assimilate Native Americans intowhite man's culture and "Americanize"them.C. to relocate the remaining NativeAmericans to the east coast.D. to authorize U.S. Colonel GeorgeCuster to capture all Native Americans. What are the cons of a mixed market for most citizens? an altitude is drawn from the vertex of an isosceles triangle forming a right angle and two congruent triangles. as a result, the altitude cuts the base into two equal segments. the length of the altitude is 30 inches, and the length of the base is 10 inches. find the triangles perimeter. round to the nearest tenth of an inch. credit card judgement can they garnish my bank account if my only income is social security in california During the time period of the Vietnam war, ___ people were killed on US highways that were killed in action in Vietnam. Is 10 24 26 a right triangle? How does East Egg affect the characters? The first laptop ever was sold was the Osborne 1. It came onto the market in 1981, and it had a mass of 11 kg. Suppose that since 1981 the mass of laptops has decreased at an average rate of 4. 7% per year. What was the approximate weight of a laptop in 2019?