Question

You have piano lessons every fourth day and guitar lessons every sixth day. Today you have both lessons. In how many days will you have both lessons on the same day again

Answer 1

The day when both occur will be the minimum common multiple (MCM) of 4 and 6.

 

4 = 22

6 = 2 x 3

 

MCM = 2 x 2 x 3 = 12

 

They will both occur on the same day every 12 days.