The price of a can of soup was increased by 20%. How many cans can be purchased for the amount of money that used to buy 300 cans?
A. 280
B. 270
C. 250
D. 240
E. 230
Solution Assume that a can of soup used to cost $1 and that it now cost $1.20 (20% more). Then 300 cans of soup used to cost $300. How many cans costing $1.20 each can be bought for $300: 300 ÷ 1.20 = 250.
During a sale a clerk was putting new price tag on each item. On one radio, he accidentally raised the price by 15% instead of lowering the price by 15%. As a result the price on the tag was $45 too high. What was the original price, in dollar, of the radio?
A. 100
B. 120
C. 150
D. 200
E. 250
Solution If p represents the original price, the radio was priced at 1.15p instead of .85p. Since there was a $45 difference:45 = 1.15p - .85p = 0.3p p = 45 ÷ .30 = 150.
If 25 students took an exam and 4 of them failed, what percent of them passed?
A. 83%
B. 84%
C. 86%
D. 90%
E. 92%
Solution If 4 students failed, then the other 25 – 4 = 21 student passed, and 21/25= 0.84 = 84%.
On a test consisting of 80 questions, Marie answered 75% of the first 60 questions correctly. What percent of the other 20 did she need to answer correctly for her grade on the entire exam to be 80%?
A. 85%
B. 87.5%
C. 90%
D. 95%
E. 100%
To earn 80% on the entire exam, Marie needs to correctly answer 64 questions (80% of 80). So far, she has answered 45 questions correctly (75% of 60). Therefore, on the last 20 questions she needs 64 – 45 = 19 correct answer; and 19/20 = 95%. The correct answer is D.
9 is 1/3 % of what number?
A. 0.03
B. 0.27
C. 3
D. 300
E. 2700
9 =(1/3)x/100 = 1x/300 ⇒ x = 9 × 300 = 2700
