Question

In a 500 metres race, B starts 45 metres ahead of A, but A wins the race while B is still 35 metres behind. What is the ratio of the speeds of A to B assuming that both start at the same time?
1. 25 ∶ 21
2. 25 ∶ 20
3. 5 ∶ 3
4. 5 ∶ 7

Answer 1

Correct Answer - Option 1 : 25 ∶ 21

Given :  

Total distance = 500m

Concept:

If the Time is constant, Speed is directly proportional to Distance

D = S × T

Calculation

A starts the race from starting point, so the Distance covered by A = 500m

Distance covered by B = 500 – 45 – 35 = 500 - 80 = 420

The ratio of distance covered by both A  and B is = 500 : 420

So, the ratio of the speed of A and B will be = 500 : 420

⇒ 25 : 21

∴ The Required answer is 25 : 21