Given set (2, 17, 31) is a set of:
(a) Prime numbers
(b) Whole numbers
(c) Odd numbers
(d) Even numbers
Choose the correct answer from the options given below :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (a) and (b) only
The set is of a kind only if every one of its members, 2, 17 and 31, is of that kind.
(a) Prime numbers Correct. Each of 2, 17 and 31 has only two factors, 1 and itself; 2 is the only even prime.
(b) Whole numbers Correct. Whole numbers are 0, 1, 2, 3, …, so every counting number is a whole number.
(c) Odd numbers Incorrect. 17 and 31 are odd, but 2 is even.
(d) Even numbers Incorrect. Only 2 is even; 17 and 31 are odd.