(1) Point C is 40 feet above the ground.
(2) x = 60
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Squirrel on a Wire
This topic has expert replies
-
hansoo
- Official Company Rep
- Posts: 37
- Joined: Sat Jun 27, 2009 4:04 pm
- Location: Berkeley, CA
- Thanked: 2 times
- Followed by:4 members
- GMAT Score:760
A squirrel climbs a straight wire from point A to point C. If B is the midpoint of AC, how far above the ground is point B?
(1) Point C is 40 feet above the ground.
(2) x = 60
(1) Point C is 40 feet above the ground.
(2) x = 60
Last edited by hansoo on Sun Sep 13, 2009 5:47 pm, edited 1 time in total.
-
ronaldo780
- Junior | Next Rank: 30 Posts
- Posts: 12
- Joined: Sun Jun 21, 2009 1:27 am
- Thanked: 1 times
It's actually A.
Regardless of what angle x is, B is always the midpoint on AC and hence also the mid point in terms of height, so its height is 20.
To prove it I drew two lines from B to D and E. Now, CEB and BDA are identical because they have two equal angles (<DAB=<EBC=x, <ECB=<DBA=90-x) and an equal side (AB=BC).
Hence, DB=EC, and since all angles are 90 DBFE is a rectangle, DB=EF, so FC=40 and DB=1/2FC=20.
(i) is sufficient and (ii) isn't.
Regardless of what angle x is, B is always the midpoint on AC and hence also the mid point in terms of height, so its height is 20.
To prove it I drew two lines from B to D and E. Now, CEB and BDA are identical because they have two equal angles (<DAB=<EBC=x, <ECB=<DBA=90-x) and an equal side (AB=BC).
Hence, DB=EC, and since all angles are 90 DBFE is a rectangle, DB=EF, so FC=40 and DB=1/2FC=20.
(i) is sufficient and (ii) isn't.
