hazelnut wrote:
If a, b, and c are positive integers and \(\frac{a}{6} + \frac{b}{5} = \frac{c}{30}\), is c divisible by 5?
(1) b is divisible by 5.
(2) a is even.
Analyzing the question stem:
\(\frac{a}{6} + \frac{b}{5} = \frac{c}{30}\) .......Multiply by 30
\(5a + 6b = c\)
C is multiple of 5, if both terms are multiple of 5....... We see that (5a) is multiple of 5, so (6b) must be multiple of b to make c divisible by 5
The question could rephrased:
Is B multiple of 5??
(1) b is divisible by 5.
This directly answers the question.
Sufficient
(2) a is even.
...
