Answer:
11 a.m.
Step-by-step explanation:
Duration of Primary Period = 40 min
Duration of Senior Section =1 hour = 60 min
To find out when the next bell will ring together, we first determine the LCM of 40 and 60.
Multiples of 40 are: 40,80,120,160,...
Multiples of 60 are: 60, 120, 180, 240...
From the above, we observe that the bell will ring together exactly 120 Minutes after 9 a.m.
Therefore:
9+120 Min =9 +2 Hours =11 a.m.
Therefore, the bell of the primary section and senior section will ring together at exactly 11 am.
