BTGmoderatorDC wrote:
In the figure above, the angle marked at c has been created by extending the base of the triangle, as shown. What is the sum of a, b, and c?
(1) a = 85
(2) b = 60
Target question: What is the sum of a, b, and c?
This is a good candidate for
rephrasing the target question.
Since angles on a line add to 180°, we already know that b + c = 180
We get: a + b + c = a + 180
So, in order to find the sum of a, b and c,
we need only find the value of a
REPHRASED target question: What is the value of a?
Aside: Here's a video with tips on rephrasing the target question: https://www.gmatprepnow.com/module/gmat- ... cy?id=1100
Statement 1: a = 85
Perfect! The answer to the REPHRASED target question is
a = 85
Since we can answer the
REPHRASED target question with certainty, statement 1 is SUFFICIENT
Statement 2: b = 60
We have no information about a
Since we cannot answer the
REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
