I did these, but the answers I got didn't match the ones in the back of the book.

If 135 is decreased by 75%, what is the new amount?

A number is decreased by 40% to 525. What is the original amount?

The cost of a pound of nails increased from $2.36 to $2.53. What is the percent of increase to the nearest whole-number percent?

Bert Davis is getting a 4.5% raise. His current salary is $38,950. How much will his raise be?

Federal Department Stores dropped the price of a winter coat by 15% to $149. What was the original price to the nearest cent?

1)

135 * 0.233 = 33.75

2)
0.6x = 525
x = 525/0.6
x = 875

Do those answers agree with the answers in your book?

If so, you can refigure the rest.

Yes, thank you.

To find the answer to these questions, we need to use some basic math operations and make sure we understand the concepts involved. Let's go through each question step by step and calculate the answers.

First question:

If 135 is decreased by 75%, what is the new amount?

To find the new amount, we can multiply 135 by 0.75 since a 75% decrease is equivalent to multiplying by (100% - 75%) or 0.75.

New amount = 135 * 0.75
= 101.25

The new amount is 101.25.

If the answer you got doesn't match the one in the back of the book, double-check if you correctly applied the percentage decrease and performed the calculation accurately.

Second question:

A number is decreased by 40% to 525. What is the original amount?

To find the original amount, we need to undo the decrease of 40%. When a number is decreased by 40%, it is multiplied by (100% - 40%) or 0.60.

Original amount = 525 / 0.60
= 875

The original amount is 875.

Again, if your answer doesn't align with the one in the book, recheck if you correctly applied the percentage decrease formula and performed the calculation accurately.

Third question:

The cost of a pound of nails increased from $2.36 to $2.53. What is the percent of increase to the nearest whole-number percent?

To find the percent of increase, we need to calculate the difference between the new price and the original price and then express it as a percentage of the original price.

Difference in price = New price - Original price
= $2.53 - $2.36
= $0.17

Percent of increase = (Difference in price / Original price) * 100
= ($0.17 / $2.36) * 100
≈ 7.20%

The percent of increase, to the nearest whole-number percent, is 7%.

If your answer doesn't match the one in the book, make sure you accurately calculated the price difference and correctly expressed it as a percentage.

Fourth question:

Bert Davis is getting a 4.5% raise. His current salary is $38,950. How much will his raise be?

To find the raise, we multiply his current salary by the percentage increase.

Raise amount = Current salary * Percentage increase
= $38,950 * 0.045

Raise amount ≈ $1,757.75

Bert's raise amount is approximately $1,757.75.

If your answer doesn't align with the one in the book, recheck if you correctly multiplied the current salary by the percentage increase and performed the calculation accurately.

Fifth question:

Federal Department Stores dropped the price of a winter coat by 15% to $149. What was the original price to the nearest cent?

To find the original price, we need to undo the 15% decrease. When a price is decreased by 15%, it is multiplied by (100% - 15%) or 0.85.

Original price = $149 / 0.85

Original price ≈ $175.29 (to the nearest cent)

The original price, to the nearest cent, is $175.29.

If your answer doesn't match the one in the book, make sure you correctly performed the calculation to find the original price after undoing the percentage decrease.

Remember, accuracy in calculation and correctly applying the percentage formulas are crucial in finding the correct answers.