<< Chapter < Page Chapter >> Page >

At "super-long play," 2 1 2 size 12{2 { {1} over {2} } } {} hours of play of a video cassette recorder represents 31.25% of the total playing time. What is the total playing time?

8 hours

Exercises

For the following 25 problems, find each indicated quantity.

What is 21% of 104?

21.84

What is 8% of 36?

What is 98% of 545?

534.1

What is 143% of 33?

What is 10 1 2 size 12{"10" { {1} over {2} } } {} % of 20?

2.1

3.25 is what percent of 88?

22.44 is what percent of 44?

51

0.0036 is what percent of 0.03?

31.2 is what percent of 26?

120

266.4 is what percent of 74?

0.0101 is what percent of 0.0505?

20

2.4 is 24% of what number?

24.19 is 41% of what number?

59

61.12 is 16% of what number?

82.81 is 91% of what number?

91

115.5 is 20% of what number?

43.92 is 480% of what number?

9.15

What is 85% of 62?

29.14 is what percent of 5.13?

568

0.6156 is what percent of 5.13?

What is 0.41% of 291.1?

1.19351

26.136 is 121% of what number?

1,937.5 is what percent of 775?

250

1 is what percent of 2,000?

0 is what percent of 59?

0

An item of clothing is on sale for 10% off the marked price. If the marked price is $14.95, what is the sale price? (Round to two decimal places.)

A grocery clerk, who makes $365 per month, re­ceives a 7% raise. How much is her new monthly salary?

390.55

An item of clothing which originally sells for $55.00 is marked down to $46.75. What percent has it been marked down?

On a 25 question exam, a student gets 21 correct. What percent is this?

84

On a 45 question exam, a student gets 40%. How many questions did this student get correct?

A vitamin tablet, which weighs 250 milligrams, contains 35 milligrams of vitamin C. What per­cent of the weight of this tablet is vitamin C?

14

Five years ago a secretary made $11,200 an­nually. The secretary now makes $17,920 an­nually. By what percent has this secretary's sal­ary been increased?

A baseball team wins 48 3 4 size 12{"48" { {3} over {4} } } {} % of all their games. If they won 78 games, how many games did they play?

160

A typist was able to increase his speed by 120% to 42 words per minute. What was his original typ­ing speed?

A salesperson makes a commission of 12% on the total amount of each sale. If, in one month, she makes a total of $8,520 in sales, how much has she made in commission?

$1,022.40

A salesperson receives a salary of $850 per month plus a commission of 8 1 2 size 12{8 { {1} over {2} } } {} % of her sales. If, in a particular month, she sells $22,800 worth of merchandise, what will be her monthly earn­ings?

A man borrows $1150.00 from a loan company. If he makes 12 equal monthly payments of $130.60, what percent of the loan is he paying in interest?

36.28%

The distance from the sun to the earth is approx­imately 93,000,000 miles. The distance from the sun to Pluto is approximately 860.2% of the dis­tance from the sun to the Earth. Approximately, how many miles is Pluto from the sun?

The number of people on food stamps in Maine in 1975 was 151,000. By 1980, the number had decreased to 59,200. By what percent did the number of people on food stamps decrease? (Round the result to the nearest percent.)

61

In Nebraska, in 1960, there were 734,000 motor-vehicle registrations. By 1979, the total had in­creased by about 165.6%. About how many motor-vehicle registrations were there in Ne­braska in 1979?

From 1973 to 1979, in the United States, there was an increase of 166.6% of Ph.D. social scien­tists to 52,000. How many were there in 1973?

19,500

In 1950, in the United States, there were 1,894 daily newspapers. That number decreased to 1,747 by 1981. What percent did the number of daily newspapers decrease?

A particular alloy is 27% copper. How many pounds of copper are there in 55 pounds of the alloy?

14.85

A bottle containing a solution of hydrochloric acid (HCl) is marked 15% (meaning that 15% of the HCl solution is acid). If a bottle contains 65 milliliters of solution, how many milliliters of water does it contain?

A bottle containing a solution of HCl is marked 45%. A test shows that 36 of the 80 milliliters contained in the bottle are hydrochloric acid. Is the bottle marked correctly? If not, how should it be remarked?

Marked correctly

Exercises for review

( [link] ) Use the numbers 4 and 7 to illustrate the commutative property of multiplication.

( [link] ) Convert 14 5 size 12{ { {"14"} over {5} } } {} to a mixed number.

2 4 5 size 12{2 { {4} over {5} } } {}

( [link] ) Arrange the numbers 7 12 size 12{ { {7} over {"12"} } } {} , 5 9 size 12{ { {5} over {9} } } {} and 4 7 size 12{ { {4} over {7} } } {} in increasing order.

( [link] ) Convert 4.006 to a mixed number.

4 3 500 size 12{4 { {3} over {"500"} } } {}

( [link] ) Convert 7 8 size 12{ { {7} over {8} } } {} % to a fraction.

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Contemporary math applications. OpenStax CNX. Dec 15, 2014 Download for free at http://legacy.cnx.org/content/col11559/1.6
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Contemporary math applications' conversation and receive update notifications?

Ask