word problem

Question

Dr Abramson and her assistances are working on three different experiments using water. Each experiment last for 15 minutes. For the first experiment the water level must be checked every 12 seconds. For the second experiment the temperature of the water must be checked every 30 seconds, for the third experiment the color of the water must be checked every 36 seconds.  In minutes list the times all three experiments will be checked at the same time.

Answer 1

Least common multiple of 12, 30, and 36 is 180 seconds

 

That's 3 minutes