OG: In the figure shown, is l1 || l2?
This topic has expert replies
-
- Master | Next Rank: 500 Posts
- Posts: 394
- Joined: Sun Jul 02, 2017 10:59 am
- Thanked: 1 times
- Followed by:5 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
1. r = s
2. t = u
E
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
Target question: In the figure shown, is l1 || l2 ?AbeNeedsAnswers wrote: ↑Fri Jun 05, 2020 6:15 pmOG2021DS325.png
In the figure shown, is l1 || l2?
1. r = s
2. t = u
E
When I SCAN the two statements, I can see that statement 1 tells me about 2 angles created by the intersection of line_1 and line m
And statement 2 tells me about 2 angles created by the intersection of line_2 and line m
Since none of the information relates line_1 and line_2, I’m pretty sure I can identify some cases with conflicting answers to the target question.
So, I’m going to head straight to……
Statements 1 and 2 combined
Key concept: For ANY 2 intersecting lines, the opposite angles will ALWAYS be equal
There are several scenarios that satisfy BOTH statements. Here are two:
Case a:
In this case, the answer to the target question is YES, of the two lines ARE parallel
Case b:
In this case, the answer to the target question is NO, of the two lines are NOT parallel
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent