Question

In a school the duration of a class in the primary section is 40 minutes and in the middle
section it is 1 hour .If both sections begin at 9 am ,when will bell of the two sections ring
together again ?


there is no algebra used

Answer 1

Lcm of 40 and 60 = 120

which means one and half hour

so bell will ring at 10 :30

I think

Answer 2

Answer:

11 am

Step-by-step explanation:

First section: 40 min

Second section: 1 hr=60 min

Therefore, L.C.M. of 40 and 60

=120 min

=2 hr

Therefore, 2 hr after 9 am

= 11am