Problem Solving - Speed

Question

"Two cyclists race on a circular track. Brown can ride once round the track in six minutes, and Robinson in four minutes. In how many minutes will Robinson overtake Brown?"

If possible it would be lovely to have the answer to this problem ASAP.

Answer 1

Brown runs a round a track in 6 minutes

Robinson runs it in 4 minutes

in 4 minutes R rounds the track while B is at 2/3 of the track

in 6 minutes R goes another 1/2 track as B rounds the track for the first time.

in 12 minutes R goes a full 3 rounds, catching up to B as B goes around for his 2nd time

time R B

0 0 0 they start together

2 1/2 1/3

4 1 2/3

6 1.5 1

8 2 1 1/3

10 2.5 1 2/3

12 3 2 when they meet again