The second number in the given number pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number pairs, except one. Find that odd number pair.
Answer & explanation
Correct answer: option 4
THE LOGIC;
1) 3 : 7;
3 x2+1 = 7
2) 15 : 63;
15 x4+3 = 63
3) 8 : 26,
8 x3+2 = 26
3) 23 : 123,
23 x5+2 = 115 not 123
Thus, 23 : 123 is the odd one.