Ratio and Proportion MCQs - Part 3

Correct Answer: b) ₹48

Explanation:
Cost of 5 apples = ₹20.
Cost of 1 apple = ₹20 ÷ 5 = ₹4.
Cost of 12 apples = 12 × ₹4 = ₹48.

Correct Answer: b) 8 hours

Explanation:
4 machines take 12 hours.
1 machine takes 12 × 4 = 48 hours.
6 machines take 48 ÷ 6 = 8 hours.

Correct Answer: b) 12

Explanation:
8 workers take 24 days.
Total work = 8 × 24 = 192 worker-days.
Workers required for 16 days = 192 ÷ 16 = 12.

Correct Answer: d) 20 hours

Explanation:
Speed = Distance ÷ Time = 100 km ÷ 5 hours = 20 km/h.
Half speed = 10 km/h.
Time to travel 200 km = 200 ÷ 10 = 20 hours.

Correct Answer: b) 8

Explanation:
5 pumps take 12 hours.
Total work = 5 × 12 = 60 pump-hours.
Pumps required for 8 hours = 60 ÷ 8 = 7.5 ≈ 8 pumps.

Correct Answer: c) 15 : 24

Explanation:
Compound ratio of 3 : 4 and 5 : 6 is calculated by multiplying the corresponding terms:
$\mathrm{3\; \times \; 5}:\mathrm{4\; \times \; 6}$ = $15:24$.

Correct Answer: a) 48 : 105

Explanation:
Compound ratio of 2 : 3, 4 : 5, and 6 : 7 is calculated by multiplying the corresponding terms:
$\mathrm{2\; \times \; 4\; \times \; 6}:\mathrm{3\; \times \; 5\; \times \; 7}$ = $48:105$.

Correct Answer: b) 2 : 3 : 5

Explanation:
The continued ratio of 2 : 3 : 5 is the same as the original ratio.

Correct Answer: b) 3 : 4 : 5

Explanation:
The continued ratio of 3 : 4 : 5 is the same as the original ratio.

Correct Answer: a) 9 : 25

Explanation:
The duplicate ratio of 3 : 5 is calculated by squaring both terms:
$\mathrm{3²}:\mathrm{5²}$ = $9:25$.

Correct Answer: b) 16 : 49

Explanation:
The duplicate ratio of 4 : 7 is calculated by squaring both terms:
$\mathrm{4²}:\mathrm{7²}$ = $16:49$.