Two runners A and B are running on a circular track. A takes 40 seconds to complete every round and B takes 30 seconds to complete every round. If they start simultaneously at 9:00 am, then which of the following is the time at which they can meet at the starting point?

Question

Two runners A and B are running on a circular track. A takes 40 seconds to complete every round and B takes 30 seconds to complete every round. If they start simultaneously at 9:00 am, then which of the following is the time at which they can meet at the starting point? (A) 9: 05 am (B) 9: 10 am (C) 9: 15 am (D) 9: 13 am

Tardigrade Admin · Accepted Answer

LCM of 40 seconds and 30 seconds is 120 seconds, i.e., 2 minutes. ∴ A and B meet in every 2 minutes. ∴ Option (b) follows.

Q. Two runners $A$ and $B$ are running on a circular track. A takes 40 seconds to complete every round and B takes 30 seconds to complete every round. If they start simultaneously at 9:00 am, then which of the following is the time at which they can meet at the starting point?

$9 : 05 am$

$9 : 10 am$

$9 : 15 am$

$9 : 13 am$

LCM of 40 seconds and 30 seconds is 120 seconds, i.e., 2 minutes.
$∴ A$ and $B$ meet in every 2 minutes.
$∴$ Option (b) follows.

Q. Two runners A and B are running on a circular track. A takes 40 seconds to complete every round and B takes 30 seconds to complete every round. If they start simultaneously at 9:00 am, then which of the following is the time at which they can meet at the starting point?

9:05am

9:10am

9:15am

9:13am