Nycgrl wrote:. If a, b, and c are integers, is the number 3(a+b)-c divisible by 3?
(1) a + b is divisible by 3.
(2) c is divisible by 3.
The answer is B
From the question stem itself we know that a+b will be multiple of 3, therefore we just have to find the value of C.
Statement I
a + b is divisible by 3
we dont know anything about C. Insufficient.
Statement II
C is a multiple of 3, therefore 3(a+b)-c will always be a multiple of 3 hence divisible by 3.
Sufficient.
Here is rule that you can learn.
If a and b are divisible by n then a-b & a+b both will be divisible by n
