The Racing magic takes 150 seconds to circle the racing track once. The Charging bull makes 40 rounds of the track in an hour. If they left the starting point together, how many minutes will it take for them to meet at the starting point for the second time? Choose one:
A) 3  B) 6  C) 9  D) 12  E) 15

Rationale: "time taken by racing magic to make one circle = 150 seconds time taken bycharging bullto make one circle = 60 mins / 40 = 1.5 mins = 90 seconds lcm of 90 and 150 seconds = 450 seconds time taken for them to meet at the starting point for the second time = 2 * 450 = 900 seconds = 15 mins answer e"
Answer: E