Question

Three bells, toll at intervals of 36 sec, 40 sec, and 48 sec respectively. They start ringing toll at particular time. They next toll together after

• A. 18 minutes
• B. 12 minutes
• C. 6 minutes
• D. 24 minutes

Answer 1

Answer: (B)

12 minutes

Let is first find L.C.M of 36, 40, 48
$\therefore L.C.M.$ of $36,40,48$
=2$\times$2$\times$2$\times$3$\times$3$\times$5$\times$2
=720
Hence the next time the three bells will toll together after 720 sec=12min