jkelk wrote:Hi

Please help solve the attached.

Thanks,
J

If a, b, and c are integers, what is the value of a?

(1) If (a - 7)(b - 7)(c - 7) = 0 and a, b, c are all integers then,
Either (a - 7) = 0 which implies a = 7 OR
(b - 7) = 0 which implies b = 7 OR
(c - 7) = 0 in which case c = 7; NOT sufficient.

2) bc = 18 but there is no info about a; NOT sufficient.

Combining (1) and (2), if a, b or c must be 7 and bc = 18 but 18 is not a multiple of 7.
This means that neither b nor c can be 7, so value a must be 7; SUFFICIENT.

The correct answer is C.