In a race of 600 meters, A can beat B by 60 meters and in a race of 500 meters; B can beat C by 50 meters. By what number of meters will A beat C in a race of 400 meters?

A) 76 meters.

B) 89 meters.

C) 71 meters.

D) 84 meters.

Answer: A 76 Meters

Solution:

Let’s assume A finishes the 600 m race in 60 sec, then

600/60 = 10 m/sec is his speed

B traveled (600-60 = 540 m in 60 sec, therefore

540/60 = 9 m/sec is B’s speed

:

“in a race of 500 metres, B can beat C by 50 metres.”

500/9 = 55.56 sec is B’s time to finish a 500 m race

C traveled 500-50 = 450 m in 55.56 sec, therefore

450/55.56 = 8.1 m/sec is C’s speed

:

By how many will A beat C in a race of 400 metres?

400/10 = 40 sec for A to run a 400 m race

C will travel 8.1*40 = 324 m in 40 sec therefore

C will be 400-324 = 76 m behind when A crosses the finish line