There is a circular path around a sports field. Sonia takes 18 minutes to drive one round of the field, while Ravi takes 12 minutes for the same.
Suppose they both start at the same point and at the same time, and go in the same direction. After how many minutes will they meet again at the starting point?
If you read the question carefully you will find that you need to find the LCM of 18 and 12 to get the meeting time of Sonia and Ravi.
$18 = 2 \times 3 \times 3$
$12 = 2 \times 2 \times 3$
LCM of $18 , 12 = 2 \times 3 \times 3 \times 2 = 36$
Heance, Sonia and Ravi meet after 36 minutes.
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