Question

three bells ring at intervals of 12 minutes 15 minutes and 18 minutes. They rang together at 10:30a.m.They will rang next at

Answer 1

we only have to take lcm of 12&15&18
lcm of these no. will be 180 that means after 3hrs
it will rang at 1:30

Answer 2

12 : 15 : 18
and they rang together at 10:30.
so
take L.c.m of all three
Lcm will be 180

so after 3hrs they will rang together.

means at 1:30 pm