Since Nick and Sally run on the 100m straight track, and Nicks's speed is 3m / s, while Sally's speed is 2m / s, if they both start from two sides of the track, running towards each other continuously, to determine how many times they would meet each other after 10 minutes the following calculation should be performed:
30 x 20 + 2 x 20 = 60 + 40 = 100
10 minutes = 600 seconds
600/20 = X
30 = X
Therefore, they would meet 30 times after 10 minutes.
