NBT NBT Quantitative Literacy: Ratios, Proportions and Rates 5 — Questions and Answers
Question 1: A store offers 15% off the original price of R480. What is the sale price?
- R408 (Correct answer)
- R420
- R396
- R432
Correct answer: R408
Discount = 0.15 × 480 = R72; sale price = 480 − 72 = R408.
Question 2: Train A travels at 90 km/h and Train B travels at 60 km/h. If Train A departs at the same time as Train B, how much further has Train A travelled after 2.5 hours?
- 75 km (Correct answer)
- 60 km
- 50 km
- 90 km
Correct answer: 75 km
Train A: 90 × 2.5 = 225 km; Train B: 60 × 2.5 = 150 km; difference = 75 km.
Question 3: Concrete is mixed using cement, sand, and gravel in the ratio 1:2:4. How many kg of sand are needed to make 280 kg of concrete?
- 80 kg (Correct answer)
- 40 kg
- 160 kg
- 70 kg
Correct answer: 80 kg
Total parts = 1+2+4 = 7; sand = (2/7) × 280 = 80 kg.
Question 4: A school spent R9 600 on textbooks for 120 students. At this rate, how much would textbooks cost for 85 students?
- R6 800 (Correct answer)
- R7 200
- R6 500
- R7 650
Correct answer: R6 800
Cost per student = 9 600 ÷ 120 = R80; cost for 85 = 80 × 85 = R6 800.
Question 5: A car uses 9 litres of fuel per 100 km. How many litres are needed to travel 350 km?
- 31.5 litres (Correct answer)
- 35 litres
- 28 litres
- 38.5 litres
Correct answer: 31.5 litres
Fuel = (9/100) × 350 = 31.5 litres.
Question 6: A box contains blue and red marbles in the ratio 3:7. There are 42 red marbles. How many marbles are in the box in total?
- 60 (Correct answer)
- 54
- 70
- 63
Correct answer: 60
If 7 parts = 42, then 1 part = 6; total = 10 parts = 60.
Question 7: A swimming pool holds 80 000 litres and is filled by two pumps. Pump A fills at 500 L/min and Pump B at 300 L/min. How many minutes will it take to fill the pool using both pumps together?
- 100 minutes (Correct answer)
- 160 minutes
- 125 minutes
- 80 minutes
Correct answer: 100 minutes
Combined rate = 500 + 300 = 800 L/min; time = 80 000 ÷ 800 = 100 minutes.
NBT NBT Quantitative Literacy: Ratios, Proportions and Rates 5
A store offers 15% off the original price of R480.
What is the sale price?