Grade 7 Math Practice Test: Unit Rates with Fractions and Complex Fractions
- Unit Rates with Fractions
- 10 questions
- 15 minutes
This test covers finding unit rates when both quantities are fractions, simplifying complex fractions and comparing rates. Tip: a unit rate "per 1" is the first quantity divided by the second, and dividing by a fraction means multiplying by its reciprocal.
Tap an option to mark your answer. You can change your mind, or tap the same option again to leave the question blank. The correct answers and explanations appear when you finish the test.Tap an option to answer; tap it again to leave the question blank.
Your result
- 0 correct
- 0 wrong
- 0 blank
-
Question 1
Ella paints 23 of a wall in 12 hour. At this rate, how much of a wall does she paint per hour?
Correct answer: D
Divide the amount by the time: 2/3 ÷ 1/2 = 2/3 × 2 = 4/3 = 1 1/3 walls per hour. 1/3 multiplies the fractions instead of dividing, and 3/4 divides the time by the amount.
-
Question 2
A recipe uses 34 cup of sugar for every 13 cup of butter. How many cups of sugar are used per cup of butter?
Correct answer: D
Sugar per cup of butter = 3/4 ÷ 1/3 = 3/4 × 3 = 9/4 = 2 1/4 cups. 4/9 is the butter per cup of sugar, the rate the wrong way around.
-
Question 3
Omar walks 112 miles in 56 hour. What is his speed in miles per hour?
Correct answer: B
Speed = distance ÷ time = 3/2 ÷ 5/6 = 3/2 × 6/5 = 18/10 = 1 4/5 miles per hour. 1 1/4 multiplies the distance by the time.
-
Question 4
A complex fraction has 25 in its numerator and 415 in its denominator. What is its value in simplest form?
Correct answer: C
A complex fraction means division: 2/5 ÷ 4/15 = 2/5 × 15/4 = 30/20 = 3/2. 8/75 multiplies the two fractions, and 2/3 is the reciprocal of the answer.
-
Question 5
A car uses 212 gallons of gas to travel 85 miles. How many miles does it travel per gallon?
Correct answer: B
Miles per gallon = 85 ÷ 2.5 = 34. 42.5 divides by 2 and ignores the half gallon, and 212.5 multiplies instead of dividing.
-
Question 6
A 12-ounce box of cereal costs $3.30. A 20-ounce box costs $5.20. Which is the better buy?
Correct answer: C
Unit prices: $3.30 ÷ 12 = $0.275 per ounce and $5.20 ÷ 20 = $0.26 per ounce. The 20-ounce box costs less per ounce, so it is the better buy even though its total price is higher.
-
Question 7
Leo mows 38 of a lawn in 14 hour. At this rate, how long does it take him to mow the whole lawn?
Correct answer: A
Time per lawn = 1/4 ÷ 3/8 = 1/4 × 8/3 = 2/3 hour, and 2/3 of 60 minutes is 40 minutes. 1 hour 30 minutes is 3/8 ÷ 1/4 = 1 1/2, which is lawns per hour, not hours per lawn.
-
Question 8
A printer uses 15 of an ink cartridge for every 112 packs of paper. How much of a cartridge does it use per pack of paper?
Correct answer: D
Cartridge per pack = 1/5 ÷ 3/2 = 1/5 × 2/3 = 2/15. 7 1/2 is packs per cartridge, the rate the wrong way around.
-
Question 9
A faucet fills 234 gallons in 13 minute. How many gallons does it fill per minute?
Correct answer: C
2 3/4 ÷ 1/3 = 11/4 × 3 = 33/4 = 8 1/4 gallons per minute. 11/12 multiplies by 1/3 instead of dividing by it.
-
Question 10
Ana jogs 23 mile in 16 hour. Ben jogs 34 mile in 15 hour. Who jogs faster, and at what speed?
Correct answer: A
Ana: 2/3 ÷ 1/6 = 4 miles per hour. Ben: 3/4 ÷ 1/5 = 15/4 = 3 3/4 miles per hour. Ben covers more distance, but he also takes more time, so Ana is faster.
Questions you leave blank are not counted as wrong.