Question 596279
The first wheel spins at 60 rpm which means that it completes 60/60 = 1 revolution every second.


The second wheel spins at 36 rpm. So it completes 36/60 = 0.6 of a revolution every second


The third wheel spins at 24 rpm. So it completes 24/60 = 0.4 of a revolution every second.



So we have the values: 1, 0.6, 0.4


If we wait 10 seconds, then we multiply each value by 10 to get: 10, 6, 4


Now we can divide by the GCF 2 to get 5, 3, 2


This means that it will take 5 seconds for the spots to line up again (since the first number corresponds to the amount of time that has gone by in seconds)