Skip to main contentSkip to solution

'A' can run 1km in 5 minutes 20 seconds and 'B' can run the same distance in 6 minutes. How many meters start can 'A' give 'B' in a kilometer race so that they finish the race together?

Solution

✅ Correct Option: 3

A is faster than B. The goal is to find how much of a head start A should give B so that when A starts running, B is already ahead, and they both cross the finish line at the same time.

Convert times to seconds:

A's time: 5 minutes 20 seconds =(5×60)+20=320= (5 \times 60) + 20 = 320 seconds

B's time: 6 minutes =6×60=360= 6 \times 60 = 360 seconds


For them to finish together, they must take the same time. Since A is faster, A will run the full 1000 meters while B runs less distance (because B started ahead).

In A's time (320 seconds), the distance B can run needs to be calculated.


B's speed =DistanceTime= \dfrac{\text{Distance}}{\text{Time}}

=1000360= \dfrac{1000}{360} m/s

=259= \dfrac{25}{9} m/s


Distance B covers =B’s speed×A’s time= \text{B's speed} \times \text{A's time}

=1000360×320= \dfrac{1000}{360} \times 320

=1000×320360= \dfrac{1000 \times 320}{360}

=320000360= \dfrac{320000}{360}

=888.89= 888.89 meters


Head start =Total distance−Distance B runs= \text{Total distance} - \text{Distance B runs}

=1000−888.89= 1000 - 888.89

=111.11= 111.11 meters

Therefore, A can give B a head start of 111.1 meters.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question