Let's find the sixth number in the set given that the mean of a set of six numbers is 60 and the mean of the first five is 50. Let x be the sixth number. The sum of the first five numbers is 5 50 = 250.

The sum of all six numbers is 6 60 = 360. So, we have 250 + x = 360, which means x = 360 - 250 = 110. So, the sixth number in the set is 110.