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2 years ago

Donna reads a book at a rate of 20 chapters per hour.

Mathematics

2 answers:

mart [117]2 years ago

8 0

Answer:

20/1=20 1 hour read one book

Step-by-step explanation:

4 chapter read in 4 hour because 1 chapter read in one gour

Studentka2010 [4]2 years ago

5 0

Answer:

Step-by-step explanation:

When working with rates, multiplication is very useful. Rate questions will give a specific rate and then a time period. They often ask, based on the rate, what can be achieved in the given time period.

The question says that if Donna can read 20 chapters in 1 hour, how many chapters can she read in 4 hours. To solve this, you can multiply 20*4; this will show how many chapters she reads in the given time period.

Since 20*4=80, she must read 80 chapters in 4 hours.

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The height h in feet of a ball thrown vertically upward from the top of a 288-foot tall building is given by h=288+48t-16t^2 whe

mr Goodwill [35]

6 sec can take penny to strike the ground.

Solution:

Given data:

$H_0=288$ feet

$V_0=48$ feet

$h(t)=288+48t-16t^2$

Re-arrange the terms from greatest degree to smallest degree.

$h(t)=-16t^2+48t+288$

We can solve it by applying quadratic formula,

$$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Here a = –16, b = 48, c = 288

$$t=\frac{-48\pm \sqrt{48^2-4(-16)(288)}}{2(-16)}$

$$t=\frac{-48\pm \sqrt{2304+18432}}{-32}$

$$t=\frac{-48\pm \sqrt{20736}}{-32}$

$$t=\frac{-48\pm144}{-32}$

Now, write find two t's using plus and minus operation.

$$t=\frac{-48+144}{-32},\ \ t=\frac{-48-144}{-32}$

$$t=\frac{96}{-32},\ \ t=\frac{-192}{-32}$

t = –3 (or) t = 6

We cannot write time is negative. so neglect t = –3.

Therefore t = 6.

Hence 6 sec can take penny to strike the ground.

8 0

3 years ago

Determine the value of the variable that makes the equation true. 12-b=12.5

dusya [7]

Answer:

B = -.5

Step-by-step explanation:

If B is negative is cancels out the prexisting negative making it positive.

6 0

3 years ago

The sum of two numbers is 39 . The larger number is 19 more than the smaller number. What are the numbers?

4vir4ik [10]

ANSWER: The numbers are 20 and 19

39-19= 20

20+19= 39

8 0

3 years ago

Read 2 more answers

Which is NOT a major expense category?<br> housing<br> transportation<br> electricity<br> food

ruslelena [56]

That would be food! Hope this hlep!

5 0

3 years ago

Read 2 more answers

A lookout tower is 16 meters tall. Its shadow is 12 meters long. Close by, there is a wooden column that is 4 meters tall. How l

Lelechka [254]

Answer:

3 metres

Step-by-step explanation:

If we draw this out, we'll see that there are actually two similar right triangles (see attachment), which means that we can set up a proportion.

The height of the lookout tower corresponds to the height of the wooden column, while the shadow of the lookout tower corresponds to the shadow of the wooden column. We can then write:

(height of lookout tower) / (shadow of tower) = (height of column) / (shadow of column)

16 / 12 = 4 / x , where x is the shadow / unknown we want to find

Cross-multiply:

16x = 48

x = 3

The answer is thus 3 metres.

7 0

3 years ago