Question

I NEED HELP jimthompson5910

15. The price of a coat was reduced from $150 to $90. By what percentage was the price reduced?

16. Nate’s hourly pay rate was raised from $10 to $12. By what percentage was Nate’s pay raised?

17. A tree grew from a height of 8 feet to a height of 12 feet. By what percentage did the tree’s height increase?

18. This week only, the local coffee shop is reducing the price of a cup of coffee from $3 .00 to $2 .28. By what percentage is the price reduced?

19. On a sunny day, the area of a puddle decreased from 700 square inches to 560 square inches. By what percentage did the area decrease?

20. A baker increased the amount of chocolate in a recipe from 8 ounces to14 ounces. By what percentage was the amount of chocolate increased?

The price of an $8,000 car is temporarily reduced to $5,000. By what percentage is the price reduced?

22. Zoe needs to raise the reduced price of the car to its original price. By what percentage should she raise the reduced price?

Answer 1

I'll do the first four problems to get you started

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Problem 15

Answer: 40%

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Step-by-step explanation:

The price dropped by $60, since 150-90 = 60. This is the discount, which is the amount you save. Divide this over the original price ($150) and we get 60/150 = 0.40 = 40%

Therefore, the price has been reduced by 40%. If we take 40% of 150, then 0.40*150 = 60 showing that 40% of $150 is 60 dollars. This matches up with the discount value mentioned earlier. So it helps verify the answer.

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Problem 16

Answer: 20%

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Step-by-step explanation:

The pay raised by 12-10 = 2 dollars. So the percent increase is 2/10 = 0.20 = 20%

Note how 20% of 10 = 0.20*10 = 2 is the pay raise amount; meaning that 2 is 20% of 10.

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Problem 17

Answer: 50%

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Step-by-step explanation:

I'll use a formula this time, but we could follow the same idea as the previous problems. This is to give another approach.

A = old value = 8

B = new value = 12

C = percent change

C = [ (B-A)/A ] * 100%

C = [ (12-8)/8 ] * 100%

C = (4/8)*100%

C = 0.50*100%

C = 50%

50% is the same as half of the value. Note how half of 8 is 4, ie 50% of 8 = 0.50*8 = 4. So this is the amount of increase when going from 8 to 12.

Side note: The "B-A" portion in the numerator represents the change in value. We divide this change over the original amount "A" and then multiply by 100% to get the percent change we're after.

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Problem 18

Answer: 24%

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Step-by-step explanation:

I'll use the formula again

A = old value = 3.00

B = new value = 2.28

C = percent change

C = [ (B-A)/A ] * 100%

C = [ (2.28-3.00)/3.00 ] * 100%

C = (-0.72/3.00)*100%

C = -0.24*100

C = -24%

The negative percent change means we have a percent decrease. So we have a 24% decrease. Since your teacher is asking about how much the percent reduction is, we'll write the positive version of this percentage.

Problems 19 through 22 will follow the same ideas as shown in the previous problems.

Answer 2

15. 40%
16. 20%
17. 50%
18.24%
19. 20%
20. 75%
21. 37.5%
22. 60%