Answer:
11:18
Step-by-step explanation:
the lowest common multiple [meaning the nearest possible time these clocks will be ringing at the same time] of 42 and 56 is 168
(56 x 3 = 168 ; 42 x 4 = 168)
So, in 168 minutes, the clock will ring together again.
Now, we need to add 168 minutes to 08:30
(168 can be made up of 2 hours and 48 minutes [120 + 48 = 168])
08:30 + 2 hours = 10:30
10:30 + 48 minutes = 11:18
So, at 11:18, these clocks will ring together again
