Sally is a patient in a hospital.
she has to take a red pill every four hours, a blue pill every six hours and a white pill every 8 hours.
she takes a pill of each color at midday.
when will she next take a pill of each color at the same time ?

The answer for this question would be MIDDAY THE NEXT DAY. Sally will take a pill of each color at the same time midday, the next day. Here is how to find the answer. We need to find the lowest common multiple or LCM of the numbers 4, 6 and 8. 
The LCM of 4 and 8 only would be 8, but 8 is not a multiple of 6 
The LCM of 4 and 6 only would be 12, but 12 is not a multiple of 8 
The LCM of 6 and 8 only would be 24, and 24 is a multiple of 4, then 24 works. 
Therefore, it will be after 24 hours, which gives us the answer of next day, midday. Hope this answer helps.