Bluebook SAT Test Ratios, Rates, Proportional Relationships, and Units 3 — Questions and Answers
Question 1: A cyclist rides at a constant speed and covers 48 miles in 3 hours. How long, in hours, will it take the cyclist to cover 80 miles at the same speed?
- 4
- 4.5
- 5 (Correct answer)
- 5.5
Correct answer: 5
Speed = 48 ÷ 3 = 16 mph; time = 80 ÷ 16 = 5 hours.
Question 2: Alloy A contains copper and zinc in a ratio of 3:7. How many grams of copper are in 200 grams of Alloy A?
- 40 g
- 50 g
- 60 g (Correct answer)
- 70 g
Correct answer: 60 g
Copper fraction = 3/(3+7) = 3/10; copper = (3/10) × 200 = 60 g.
Question 3: A store marks up all items by 40%. If the store's cost for a jacket is $75, what is the selling price?
- $100
- $105 (Correct answer)
- $110
- $115
Correct answer: $105
Selling price = $75 × 1.40 = $105.
Question 4: A water tank loses water at a rate of 0.5 gallons per minute. How many gallons does the tank lose in 2 hours and 30 minutes?
- 60
- 65
- 70
- 75 (Correct answer)
Correct answer: 75
2 hr 30 min = 150 minutes; 0.5 × 150 = 75 gallons.
Question 5: Light travels at approximately 3 × 10⁸ meters per second. How many kilometers does light travel in 5 seconds? (1 km = 1,000 m)
- 1.5 × 10⁶ km (Correct answer)
- 1.5 × 10⁹ km
- 1.5 × 10⁸ km
- 1.5 × 10⁷ km
Correct answer: 1.5 × 10⁶ km
Distance in meters = 3×10⁸ × 5 = 1.5×10⁹ m; in km = 1.5×10⁹ ÷ 10³ = 1.5×10⁶ km.
Question 6: In a school, the ratio of boys to girls is 4:5. If there are 360 students in total, how many are boys?
- 140
- 150
- 160 (Correct answer)
- 170
Correct answer: 160
Boys = (4/9) × 360 = 160.
Question 7: A car travels 400 km on 50 liters of fuel. If the price of fuel is $1.20 per liter, what is the fuel cost per kilometer?
- $0.10
- $0.12
- $0.15 (Correct answer)
- $0.18
Correct answer: $0.15
Fuel per km = 50 ÷ 400 = 0.125 L/km; cost per km = 0.125 × $1.20 = $0.15.
Bluebook SAT Test Ratios, Rates, Proportional Relationships, and Units 3
A cyclist rides at a constant speed and covers 48 miles in 3 hours.
How long, in hours, will it take the cyclist to cover 80 miles at the same speed?