two crickets croak every 15 minutes and 20 minutes. given that they croaked at the same time 12pm, at what time would they would croak at the same time again
15=3 X 5
20=2 X 2 X 5
LCM=3 X 2 X 2 X5=60
The two crickets will chirp again together in 60 minutes or in one hour from 12pm, which will be at 1:00pm.
Thanks you guest. :)
This question is trivial but I am wondering how you would set up and solve a more difficult question like this using modular arithmetic ??
With SMALL numbers another way this can be done is to list the first few multiples of each number to see when(if) they match
example every 15 mins 15 30 45 60 75
every 20 mins 20 40 60 80 You can quickly see 60 is the first match, so the answer would be 60 minutes after 12pm ...or 1 pm