Three runners running around a circular track can complete one revolution in 2,3 and 4 hrs respectively. After how long they will meet again at the starting point?
Answers
the time they will meet together is the lcm of their hours:
number of hours: 2,3 &4
lcm of 2,3 and 4 = 12
hence they will meet in 12 hours again
Given:
Three runners running around a circular track can complete one revolution in 2,3 and 4 hrs respectively.
To find:
When will they meet again at the starting point
Solution:
To solve the question we need to realise that if the runners meet once at the starting point at the start of the race, they will meet again at the least common multiple of the time taken by all the three runners
LCM ( 2,3.4) = 12
They will meet 12 hours after the start of the race.
The number of revolutions completed by the runners will be 12 hours divided by the time they take to complete one revolution respectively.
For runner A = 12/ 2 = 6
For runner B = 12/ 3 = 4
For runner C = 12/4 = 3
Therefore, they will meet 12 hours after the start of the race, where runners A, B, C would have completed 6, 4, 3 revolutions respectively.