Aaron, Eujean and Alex were running in Machritchie Reservoir. Aaron, Eujean and Alex finished one round in 20 minutes, 36 minutes and 45 minutes respectively. Given that all of them start at 18:30 at the starting point, find the next timing that they would all meet again.
To find the next timing that they would all meet again, we need to find the least common multiple (LCM) of their finishing times.
The finishing times for Aaron, Eujean, and Alex are 20 minutes, 36 minutes, and 45 minutes, respectively.
Prime factorizing the finishing times:
20 minutes = 2^2 * 5
36 minutes = 2^2 * 3^2
45 minutes = 3^2 * 5
To find the LCM, we take the highest power of each prime factor that appears in any of the finishing times:
LCM = 2^2 * 3^2 * 5 = 4 * 9 * 5 = 180
Thus, the next timing that they would all meet again is 180 minutes after they started at 18:30.
Adding 180 minutes to 18:30, we get 21:30.
Therefore, they would all meet again at 21:30.