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

1. A. 17, 37, 47, 97
2. B. 31, 41, 53, 67
3. C. 71, 73, 79, 83
4. D. 83, 89, 91, 97

Answer: D

Explanation

To identify the different group, we examine the properties of the numbers in each option:
(a) 17, 37, 47, 97 are all prime numbers.
(b) 31, 41, 53, 67 are all prime numbers.
(c) 71, 73, 79, 83 are all prime numbers.
(d) 83, 89, 91, 97. In this group, 83, 89, and 97 are prime numbers. However, 91 is a composite number, as it can be factored into 7 × 13. Since group (d) contains a composite number while the others contain only prime numbers, it is the different group.