15.
Select the set in which the numbers are related in the same way as are the numbers of the following set.
(24, 15, 120)
(21, 19, 133)
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 โ Operations on 13 such as adding/deleting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)