Question

There is a circular path around a sports field. A takes 18 minutes to drive one round of the field, while B takes 12 minutes for the same direction, after how many minutes will they meet again at the starting point.

• A. 18
• B. 25
• C. 30
• D. 36

Answer 1

Answer: (D)

36

We will get the required answer by finding the LCM of $18$ and $12$.

$18=2\times 3\times 3$

$12=2\times 2\times 3$

$\Rightarrow$ LCM of $18$ and $12$ $=2\times 2\times 3\times 3=36$

$\Rightarrow$ They will meet again after $36$ minutes.