If A is an integer, then which of the following statements is or are always true?

1.A + 1 will be odd

2.A squared + 2 will be odd

3.A + 2 will be odd

4.2A - 1 will be odd

5.A squared + 1 will be odd

A1 & 2 only

B1, 2 & 3 only

C4 & 5 only

D4 only ✓ Correct

Correct answer: (D) 4 only

Explanation

Only Statement 4 is always true.

2A is even for any integer A.

2A - 1 is therefore always odd.

A + 1, A + 2, A^2 + 2, A^2 + 1 depend on A's parity.

Only 2A - 1 is guaranteed odd.

Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.