Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different from the rest.
Answer & explanation
Correct answer: option 2
THE LOGIC FOLLOWED HERE IS;
1) 23 : 52,
23+52 = 75(NOT PRIME NUMBER)
2) 18 : 49,
18+49 = 67(PRIME NUMBER)
3) 7 : 37,
7+37 = 44(NOT PRIME NUMBER)
4) 13 : 29,
13+29 = 42(NOT PRIME NUMBER)
Thus, 18 : 49 is the odd one.