2) In a School, the duration of each period in the Junior Section is 20 minutes and in the Senior Section it is 35 minutes. Both bells ring together when School starts at
10:30 am. The next time they ring together is at lunch time. At what time does lunch
break start?
A. 12:50 pm B. 12 noon
C. 11:40 am D. 12:30 am

n35=m20

n/m=4/7The next time they ring together⇒n=44*35=140⇄2h20p⇒a

Step-by-step explanation:

dd

(A) 12:50 pm
Step-by-step explanation:
In the above question, we are asked about that COMMON TIME in which both the bells rings together.
So, in order to find that common time, we will figure out the L.C.M. of 20 and 35.
LCM (20, 35) = 140 minutes, i.e. 2hours and 20 minutes
Now, time after a duration of 2hr and 20 min from 10:30 am =
10:30 + 2:20 = 12:50 pm