7.4D Percent Increase and Decrease

The number of people signed up for a bus trip increased from 32 to 45. What is the percent increase? Round to the nearest percent.

• 52%

• 41%

• 42%

• 45%

Answer explanation

To find the percent increase, subtract the original number (32) from the new number (45), which gives 13. Then, divide by the original number (32) and multiply by 100: (13/32) * 100 = 40.625%. Rounding gives 41%, the correct answer.

The regular price of a scooter is $65.50. It is on sale for $52.40. What is the percent decrease from the regular price to the sale price of the scooter? 

• 35%

• 25%

• 30%

• 20%

Answer explanation

To find the percent decrease, subtract the sale price from the regular price: $65.50 - $52.40 = $13.10. Then, divide the decrease by the regular price: $13.10 / $65.50 ≈ 0.20. Multiply by 100 to get 20%, the correct answer.

A shoe sales associate earned $300 in August. In September she earned 8% more than she did in August. How much did she earn in September? 

• $164

• $256

• $404

• $324

Answer explanation

In September, she earned 8% more than $300. Calculate 8% of $300: 0.08 * 300 = $24. Add this to her August earnings: 300 + 24 = $324. Therefore, she earned $324 in September.

Find the new amount given the original amount and the percent of change.
340 pages; 20% decrease 

• 320 pages

• 240 pages

• 272 pages

• 360 pages

Answer explanation

To find the new amount after a 20% decrease from 340 pages, calculate 20% of 340, which is 68. Subtract this from 340: 340 - 68 = 272 pages. Thus, the new amount is 272 pages.

What is the total price of a book if Barnes and Nobles gets it for $4.25 and the markup is 30%?

• $55.25

• $1.28

• $5.53

• $4.38

Answer explanation

To find the total price, calculate the markup: $4.25 * 0.30 = $1.28. Then add the markup to the original price: $4.25 + $1.28 = $5.53. Thus, the total price of the book is $5.53.

Discount is ____________ from the price.

• added

• divided

• subtracted

• Multiplied

Answer explanation

Discount is subtracted from the price to reduce the total amount owed. Therefore, the correct answer is 'subtracted', as it accurately describes the process of applying a discount.

Sales tax is __________ to the price

• subtracted

• added

• multiplied

• divided

Answer explanation

Sales tax is added to the price of goods or services. This means that the total amount paid by the consumer includes the original price plus the sales tax, making 'added' the correct choice.

A TV is regularly priced at $600, but it is on sale for 20% off. What's the sale price?

• $320

• $500

• $480

• $720

Answer explanation

To find the sale price, calculate 20% of $600, which is $120. Subtract this from the regular price: $600 - $120 = $480. Thus, the sale price is $480.

Mrs. Ciampa had 27 students in her class last year and this year she had 30 students in her math class. What is the percent of change?

• 24%

• 10%

• 11%

• 50%

Answer explanation

To find the percent change, use the formula: ((new value - old value) / old value) x 100. Here, ((30 - 27) / 27) x 100 = (3 / 27) x 100 ≈ 11%. Thus, the percent change is 11%.