Two trains P and Q are running on parallel tracks in opposite directions. The trains started 250 miles apart and cross each other in exactly 2 hours. Does train T cover more distance than train Q in 2 hours.
1. Train P averaged a speed of 70 miles/hr.
2. Train Q averaged a speed of 55 miles/hr.
(A) Statement 1 is sufficient in itself
(B) Statement 2 is sufficient in itself
(C) Statement 1 and 2 taken together are sufficient.
(D) Both are sufficient by themselves.
(E) Both statements are insufficient.
Target Test Prep is 20% off right now!
Use code FLASH20
Available with Beat the GMAT members only code
MORE DETAILS
Data Sufficiency Question
This topic has expert replies
-
Ankush2008
- Newbie | Next Rank: 10 Posts
- Posts: 2
- Joined: Sat Aug 02, 2008 1:38 pm
-
parallel_chase
- Legendary Member
- Posts: 1153
- Joined: Wed Jun 20, 2007 6:21 am
- Thanked: 146 times
- Followed by:2 members
I think the answer is D.
From the question stem you find that the increasing or decreasing speed between the trains is 250/2=125mph,
Therefore,
P's speed + Q's speed =125
We just have to find the speed of each train. The faster train will take less time and cover more distance.
Statement I
P's speed= 70mph
70+Q=125 => Q=55
Sufficient.
Statement II
P+55 =125 => P=70
Sufficient.
Hence D is the answer.
Let me know if you still have any doubts.
From the question stem you find that the increasing or decreasing speed between the trains is 250/2=125mph,
Therefore,
P's speed + Q's speed =125
We just have to find the speed of each train. The faster train will take less time and cover more distance.
Statement I
P's speed= 70mph
70+Q=125 => Q=55
Sufficient.
Statement II
P+55 =125 => P=70
Sufficient.
Hence D is the answer.
Let me know if you still have any doubts.
-
Vignesh.4384
- Master | Next Rank: 500 Posts
- Posts: 443
- Joined: Sat Jun 28, 2008 6:33 pm
- Thanked: 5 times
Hi Paralle_chase,
I am not able to understand your statement "From the question stem you find that the increasing or decreasing speed between the trains is 250/2=125mph" I am not able to understand it. So can you please explain?
I am not able to understand your statement "From the question stem you find that the increasing or decreasing speed between the trains is 250/2=125mph" I am not able to understand it. So can you please explain?
parallel_chase wrote:I think the answer is D.
From the question stem you find that the increasing or decreasing speed between the trains is 250/2=125mph,
Therefore,
P's speed + Q's speed =125
We just have to find the speed of each train. The faster train will take less time and cover more distance.
Statement I
P's speed= 70mph
70+Q=125 => Q=55
Sufficient.
Statement II
P+55 =125 => P=70
Sufficient.
Hence D is the answer.
Let me know if you still have any doubts.
-
parallel_chase
- Legendary Member
- Posts: 1153
- Joined: Wed Jun 20, 2007 6:21 am
- Thanked: 146 times
- Followed by:2 members
If two trains are traveling in opposite direction you add the speeds of both the trains to find the increasing or decreasing speed.
If two trains are 250 miles apart and they pass each in exactly two hours.
The increasing or decreasing speed = D/T =250/2 =125
If the two trains were traveling in the same direction then you would subtract the speeds of both the trains.
The speed is increasing or decreasing because when the trains traveling in opposite direction the distance is decreasing between them but when the two trains have passed each other the distance is actually increasing.
Hope this helps, let me know if you still have any doubts.
If two trains are 250 miles apart and they pass each in exactly two hours.
The increasing or decreasing speed = D/T =250/2 =125
If the two trains were traveling in the same direction then you would subtract the speeds of both the trains.
The speed is increasing or decreasing because when the trains traveling in opposite direction the distance is decreasing between them but when the two trains have passed each other the distance is actually increasing.
Hope this helps, let me know if you still have any doubts.
