BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

please help with several math problems

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Tue Jan 22, 2008 10:11 am

please help with several math problems

by uria » Sun Mar 30, 2008 5:24 pm
DS Question:
On the number line, the distance between point A and point C is 5 and the distance between point B and C is 20. Does point C lie between point A and point B?
1. The distance between point A and point B is 25.
2. Point A lies to the left of B.

PS Question:
A hiker walking at a constant rate of 4 miles per hour is passed by a cyclist traveling in the same direction along the same path at a constant rate of 20 miles per hour. The cyclist stops to wait for the hiker 5 min after passing her, while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?
6 2/3
15
20
25
26 2/3


Thanks in advance....
Top
Source: — Quantitative Reasoning |
Senior | Next Rank: 100 Posts
Posts: 57
Joined: Tue Jun 26, 2007 11:33 pm
Thanked: 4 times

by madhavi » Mon Mar 31, 2008 8:23 am
PS Q:

The hiker travels for (20*5)/60 miles =5/3 miles in 5 min before he waits for the hiker.

The hiker travles (4*5)/60 miles =1/3 miles in the meantime.

So, the cyclist needs to wait until the hiker cover (5/3)-(1/3) miles ie 4/3 miles

To cover this distance the hiker needs, (4/3)* (60/4) =20min

https://goal-mba.blocked
Top
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Tue Jan 22, 2008 10:11 am

by uria » Mon Mar 31, 2008 11:35 am
thanks a lot
Top
Junior | Next Rank: 30 Posts
Posts: 18
Joined: Sat Mar 15, 2008 10:54 pm

by spanlength » Thu Apr 03, 2008 11:16 pm
DS Q:

Here we can see that since A and B are 25 units apart.So C lies between them.

Regarding their position nothing can be inferred from the information provided.

QS Q.

Also here i would like to sujjest that subtracting the speed will directly give u difference in distance.

(20-4) * 5/60 = 4/3 .
Top
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Mon Feb 04, 2008 5:46 pm
Location: st petersburg fl
Followed by:1 members

by gabriela13 » Tue May 11, 2010 6:43 am
Hi,

The way I think of these kind of rates is a little diffrent:
Hiker: Rate 4 miles an hour
Biker: Rate 20 miles per hoer
In 5 minutes the biker covers 5/20 of a mile which is 1/4 of a mile. The hiker walks 5 times slower (20 miles of the biker divided by 4 miles walked by the walker:-)..) so he would need 5*4 minutes
Good luck to you all (now working on the gmat) and thank you all (who took it).
Top
User avatar
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Thu Apr 10, 2008 6:23 am
GMAT Score:800

by hephzi_bah » Wed May 12, 2010 7:26 am
uria wrote:DS Question:
On the number line, the distance between point A and point C is 5 and the distance between point B and C is 20. Does point C lie between point A and point B?
1. The distance between point A and point B is 25.
2. Point A lies to the left of B.

PS Question:
A hiker walking at a constant rate of 4 miles per hour is passed by a cyclist traveling in the same direction along the same path at a constant rate of 20 miles per hour. The cyclist stops to wait for the hiker 5 min after passing her, while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?
6 2/3
15
20
25
26 2/3


Thanks in advance....
My humble answer to you... DS

Image

Sincerely
Alberto Vidal
Top
User avatar
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Thu Apr 10, 2008 6:23 am
GMAT Score:800

by hephzi_bah » Wed May 12, 2010 7:42 am
uria wrote:DS Question:
On the number line, the distance between point A and point C is 5 and the distance between point B and C is 20. Does point C lie between point A and point B?
1. The distance between point A and point B is 25.
2. Point A lies to the left of B.

PS Question:
A hiker walking at a constant rate of 4 miles per hour is passed by a cyclist traveling in the same direction along the same path at a constant rate of 20 miles per hour. The cyclist stops to wait for the hiker 5 min after passing her, while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?
6 2/3
15
20
25
26 2/3


Thanks in advance....
This is my answer to your PS question

Image

Sincerely
Alberto Vidal
the800test.com
Top
User avatar
GMAT Instructor
Posts: 1052
Joined: Fri May 21, 2010 1:30 am
Thanked: 335 times
Followed by:98 members

by Patrick_GMATFix » Fri May 21, 2010 10:53 am
Hey Uria.

Consider posting one question per thread, to help keep the discussion as clear as possible.

Both of the problems you submitted are pretty tough, but I hope the videos that show step by step solutions will be helpful.

These are QID 1046 (with correct answer A) and QID 1248 (with correct answer C)

-Patrick
Top
Master | Next Rank: 500 Posts
Posts: 112
Joined: Wed Jan 20, 2010 5:46 am
Thanked: 1 times

by Thouraya » Tue May 31, 2011 6:16 am
@Patrick_GMATFix,

I have a question regarding the DS question if you dont mind. I understand why A is sufficient, but why isn't B sufficient?

From the given, we can draw the following options:

B--------A-----C---------B

or B------C-------A

Statement B says that A is to the left of B. The only option where A is to the left of B is when C is in the middle, thus sufficient. Or is it that I can't assume that because in drawing 2, C is between B and A; yet A is to the right? Would appreciate your explanation, Thank you!
Top
Post new topic Post Reply
• Page 1 of 1