Three of the following four options are alike in a certain way and thus form a group. Which is the one that does NOT belong
to that group?
(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.)
1
81 – 118 – 91
2
52 – 68 – 51
3
99 – 104 – 71
4
21 – 38 – 31