NBT NBT Quantitative Literacy: Ratios, Proportions and Rates 2

Question 1

R12 000 is divided among three siblings in the ratio 1:3:2. How much does the sibling with the largest share receive?

Accepted Answer

R6 000

Answer

Total parts = 1+3+2 = 6; largest share = 3/6 × 12 000 = R6 000.

Question 2

A cyclist rides at a constant speed of 18 km/h. How many minutes does it take to cover 9 km?

Accepted Answer

30 minutes

Answer

Time = 9 ÷ 18 = 0.5 hours = 30 minutes.

Question 3

A photograph 8 cm wide and 12 cm tall is enlarged so that the width becomes 20 cm. What is the new height?

Accepted Answer

30 cm

Answer

Scale factor = 20 ÷ 8 = 2.5; new height = 12 × 2.5 = 30 cm.

Question 4

A tap fills a 240-litre tank in 4 hours. What is the flow rate of the tap in litres per minute?

Accepted Answer

1 litre per minute

Answer

Rate = 240 ÷ (4 × 60) = 240 ÷ 240 = 1 litre per minute.

Question 5

Paint is mixed in the ratio 5 parts white to 2 parts red. How many millilitres of red paint are needed to make 350 ml of the mixture?

Accepted Answer

100 ml

Answer

Red fraction = 2/(5+2) = 2/7; red needed = (2/7) × 350 = 100 ml.

(NBT) National Benchmark Test Practice Test