Question

Is the integer n divisible by 3?
(1) the last digit in n is 3.
(2) n+5 is divisible by 6.

• A. Statement (1) alone is sufficient, but statement (2) alone is not sufficient.
• B. Statement (2) alone is sufficient, but statement (1) alone is not sufficient.
• C. Both statements together are sufficient, but neither statement alone is sufficient.
• D. Statement (1) and (2) together are not sufficient.

Answer 1

Answer: (D)

Statement (1) and (2) together are not sufficient.

(1) $\Rightarrow$ Last digit of n is 3
$\Rightarrow$ n may be 3, 13, 23, 33, 43, 53, 63, ......
(2) $\Rightarrow n+5$ is divisible by 6
$\Rightarrow$ n may be 1, 7, 13, 19, 25, 31, 37, 43, ......
Hence, we cannot be determined that integer is divisible by 3 even using both the statements.