question_answer

The traffic lights at three different road crossings change after every 48 seconds, 72 seconds, 108 seconds respectively. If they change simultaneously at 7 a.m. after what time they will change simultaneously again?

A)  7 min, 12 sec.   

B)  7 min, 18 sec.

C)  7 min, 24 sec.  

D)  6 min, 48 sec.