Question

three bells tolls at intervals of 9,12,15 minutes respectively if they start tolling together after what time will they next toll togethr

Answer 1

9.,....................

Answer 2

it is simple

first we should take lcm of
3/9,12,15
/3,4,5
lcm=3*3*4*5
=180
after 180 minutes
i.e. after 3 hours

hope it will help you