Select the set in which the numbers are related in the same way as are the numbers of the following sets.
(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 - Operations on 13 such as adding/ subtracting/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.)
13 - 15 - 7 and 9 - 11 - 5
1
16 - 24 - 10
2
15 - 18 - 9
3
26 - 37 - 15
4
22 - 45 - 21