If a, b, and c are integers, what is the value of a?
(i) (a-7)(b-7)(c-7) = 0
(ii) bc = 18
(i) (a-7)(b-7)(c-7) = 0
(ii) bc = 18
(1) Here, it can be true even if a is not 7, and any one of b and c or both, is 7. So, when a is not 7, what's a? Still unsolved. Insufficientabhasjha wrote:If a, b, and c are integers, what is the value of a?
(i) (a-7)(b-7)(c-7) = 0
(ii) bc = 18
(2) This tells absolutely nothing about a. Insufficient
Taken together
Neither b nor c can take the value 7, as these are integers and their product is 18, which doesn't have 7 as a factor. Hence, x can only be 7 in order to prove info in (1), as true. Sufficient
[spoiler]C[/spoiler]
