Question

A motorcycle covers a certain place in 51 hours. If speed of the motorcycle get reduced by (4/17)^th, it goes 60 km less in that time. Find speed of the motorcycle.

A. Speed required to cover 75 km in 15 h

B. Speed required to cover 60 km in 12 h

C. 8 km/h

D. 10 km/h

1. A and B
2. C
3. A
4. B and D

Answer 1

Correct Answer - Option 1 : A and B

Given:

Time motorcycle takes to cover the distance = 51 h

Calculation:

Let 51x be the distance covered

Distance covered when speed is reduced = {1 – (4/17)} × 51x = (13/17) × 51x

⇒ Distance covered with new speed = 39x

51x – 39x = 60

⇒ 12x = 60

⇒ x = 5

A. Speed required to cover 75 km in 15 h

Speed = 75/15 = 5km/hr

A is correct.

B. Speed required to cover 60 km in 12 h

Speed = 60/12 = 5km/hr

B is correct.

∴ A and B is correct.