question_answer

Samantha, Jessica and Roseline begin to jog around a circular stadium. They complete their revolutions in 84 s, 56 s and 63 s respectively. After how many seconds will they be together at the starting point?

A)  336                  

B)  504

C)  252                  

D)  Cannot be determined

Correct Answer: B

Solution :

\[\therefore \] LCM \[=2\times 2\times 2\times 3\times 3\times 7=504\] Hence, they will meat after 504 s.