AbeNeedsAnswers wrote: ↑Sun May 05, 2019 9:15 pm
In the figure above, RST is a triangle with angle measures as shown and PRTQ is a line segment. What is the value of x + y ?
(1) s = 40
(2) r = 70
A
Source: Official Guide 2020
Given: RST is a triangle with angle measures as shown and PRTQ is a line segment
Target question: What is the value of x + y ?
Statement 1: s = 40
Since angles in a triangle add to 180°, we know that
r° + t° = 140°
Since angles on a line add to 180°, we know that
x° + r° = 180°, and we know that
t° + y° = 180°
So, we can write: x° + r° + t° + y° = 180° + 180°
Rearrange: x° + y° +
r° + t° = 360°
Substitute to get: x° + y° +
140° = 360°
Subtract 140° from both sides to get:
x° + y° = 220°
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: r = 70
This tells us that x° = 110°, however we have no information about the value of any other angle.
Statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
