Question

An aeroplane covers a certain distance in 5 hrs travelling at 280 km/h. But due to an emergency it had to cover the same distance in 2 hrs 48 min. What should be the speed of the plane?

1. 600 km/h
2. 500 km/h
3. 400 km/h
4. 450 km/h

Answer 1

Correct Answer - Option 2 : 500 km/h

Given:

Initial speed of the plane = 280 km/h

Initial time taken = 5 hrs

New time taken = 2 hrs 48 min = 14/5 hrs

Formula used:

Speed × time = Distance travelled

Calculation:

Let the new speed of the plane = y km/h

∵ the distance travelled is same.

∴ 280 km/h × 5 hr = y × (14/5) hrs

⇒ y = (280 × 5 × 5)/14

⇒ y = 500 km/h