Q. Choose the group which is different from the others:
(a) 17, 37, 47, 97
(b) 31, 41, 53, 67
(c) 71, 73, 79, 83
(d) 83, 89, 91, 97
Correct Answer: (d) 83, 89, 91, 97
Question from UPSC Prelims 2023 CSAT
Explanation :
All the numbers in options (a), (b), and (c) are prime numbers. However, in option (d), 91 is not a prime number, so it is different from the others.