Question

$A$, $B$ and $C$ start at the same time in the same direction to run around a circular stadium. A completes a round in $252$ seconds, $B$ in $308$ seconds and $C$ in $198$ seconds, all starting at the same point. After what time will they again be at the starting point?

• A. $26$ minutes and $18$ seconds
• B. $42$ minutes and $36$ seconds
• C. $45$ minutes
• D. $46$ minutes and $12$ seconds

Answer 1

Answer: (D)

$46$ minutes and $12$ seconds

L.C.M. of $252$, $308$ and $198=2772$.
So, $A$, $B$ and $C$ will again meet at the starting point in $2772$ sec. i.e., $46$ min. $12$ sec.