GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 14 Nov 2018, 06:04

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• \$450 Tuition Credit & Official CAT Packs FREE

November 15, 2018

November 15, 2018

10:00 PM MST

11:00 PM MST

EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth \$100 with the 3 Month Pack (\$299)
• Free GMAT Strategy Webinar

November 17, 2018

November 17, 2018

07:00 AM PST

09:00 AM PST

Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

A 2 Part question

Author Message
TAGS:

Hide Tags

e-GMAT Representative
Joined: 02 Nov 2011
Posts: 2734

Show Tags

01 Jan 2013, 21:48
Hello friend,

Please try this 2 part question...

A can beat B in a 400 yards race by 60 yards, B can beat C in a 850 yards race by 100 yards, whereas C can beat D in a 600 yards race by 40 yards. Select the values of 'A beats C', & 'B beats D' by yards in a 200 yards race in the table that are consistent with the information provided.
Make only two selections, one in each column.

-Shalabh
_________________

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Intern
Joined: 30 Aug 2007
Posts: 4
Re: A 2 Part question  [#permalink]

Show Tags

03 Jan 2013, 17:50
1
This is the longer version of solution , there is a quick way to do it also :

Lets say As is the speed of A , Bs is the speed of B and similarly Cs is for C & Ds is for D.

if A took T1 time to finish the 400 yards race , so in the same time B will cover 340 yards

Therefore, we can say that T1 = 400/As and T1 = 340/Bs (Speed = Distance/Time or Time = Distance/speed ).

T1 = 400/As = 340/Bs => As/Bs = 400/340 or As/Bs = 20/17

Similarly , we can get

Bs/Cs = 17/15 & Cs/Ds= 15/14

therefore we can say , As/Cs = 4/3 ( As = 20/17 * Bs = 20/17 * 17/15 * Cs = 20/15 Cs

Lets assume to complete a 200 yards race A took time T , then

As=200/T or T = 200/As , in the same time C will cover X distance , so X = Cs * T (Distance = Speed * time)

Therefore X = Cs * 200/As ( from above we knw that As/Cs = 4/3 )

X = 200 / (As/Cs) = 200 / (4/3) = 150.

Thereby we can say that A will beat C in a 200 yards race by 50 yards.

Similarly we can get that B will beat D in a 200 yards race by 35 yards.
e-GMAT Representative
Joined: 02 Nov 2011
Posts: 2734
Re: A 2 Part question  [#permalink]

Show Tags

04 Jan 2013, 00:19
3
punwish wrote:
This is the longer version of solution , there is a quick way to do it also :

Lets say As is the speed of A , Bs is the speed of B and similarly Cs is for C & Ds is for D.

if A took T1 time to finish the 400 yards race , so in the same time B will cover 340 yards

Therefore, we can say that T1 = 400/As and T1 = 340/Bs (Speed = Distance/Time or Time = Distance/speed ).

T1 = 400/As = 340/Bs => As/Bs = 400/340 or As/Bs = 20/17

Similarly , we can get

Bs/Cs = 17/15 & Cs/Ds= 15/14

therefore we can say , As/Cs = 4/3 ( As = 20/17 * Bs = 20/17 * 17/15 * Cs = 20/15 Cs

Lets assume to complete a 200 yards race A took time T , then

As=200/T or T = 200/As , in the same time C will cover X distance , so X = Cs * T (Distance = Speed * time)

Therefore X = Cs * 200/As ( from above we knw that As/Cs = 4/3 )

X = 200 / (As/Cs) = 200 / (4/3) = 150.

Thereby we can say that A will beat C in a 200 yards race by 50 yards.

Similarly we can get that B will beat D in a 200 yards race by 35 yards.

Hi punwish,

That's the correct answer. Yes, you are right this is a longer method to approach the question. I think the approach below is smarter one.

We can find out the continued ratios of all 4 players.

--A--:---B--:---C--:---D----
400 : 340
------:850 : 750
------:-----: 600 : 560
------------------------------------
400 : 340 : 750/850*340 : --
400 : 340 : 300 : 560/600*300
400 : 340 : 300 : 280

So. we can infer that A beats C by 100 yards in a 400 yard race, so it will beat C by 50 yards in a 200 yard race.

Similarly, we can infer that B beats D by 60 yards in 340 yard race, so it will beat D by (340-280)/340*200 = ~35 yards in a 200 yard race.

Meanwhile, don't forget to attend the SC session on Saturday. Please find the link below:

-Shalabh
_________________

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Intern
Joined: 19 May 2012
Posts: 30
Location: India
GMAT Date: 03-03-2014
WE: Information Technology (Computer Software)
Re: A 2 Part question  [#permalink]

Show Tags

08 Jan 2013, 21:26
50 and 35
just find out by how much each beats other in 200yards race...
easy one....
_________________

Thanks
crazy4priya
GMATPrep 1 710/Q49/V38
GMATPrep 2 690/Q49/V34
Veritas Prep 700/Q50/V36/IR5
MGMT Test 1 700/Q51/V35/IR3

e-GMAT Representative
Joined: 02 Nov 2011
Posts: 2734
Re: A 2 Part question  [#permalink]

Show Tags

08 Jan 2013, 22:21
1
Shashank3016 wrote:
egmat wrote:
--A--:---B--:---C--:---D----
400 : 340
------:850 : 750
------:-----: 600 : 560
------------------------------------
400 : 340 : 750/850*340 : --
400 : 340 : 300 : 560/600*300
400 : 340 : 300 : 280

That was a very quick method Shalabh. Thanks!

Thank you Shashank. By the way do not forget to attend following event this weekend to learn how to improve by up to 70 points in 25 days. Pl. click to know more.

-Shalabh Jain
_________________

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Manager
Joined: 15 Dec 2016
Posts: 88

Show Tags

14 Nov 2017, 17:19
egmat wrote:
punwish wrote:
This is the longer version of solution , there is a quick way to do it also :

Lets say As is the speed of A , Bs is the speed of B and similarly Cs is for C & Ds is for D.

if A took T1 time to finish the 400 yards race , so in the same time B will cover 340 yards

Therefore, we can say that T1 = 400/As and T1 = 340/Bs (Speed = Distance/Time or Time = Distance/speed ).

T1 = 400/As = 340/Bs => As/Bs = 400/340 or As/Bs = 20/17

Similarly , we can get

Bs/Cs = 17/15 & Cs/Ds= 15/14

therefore we can say , As/Cs = 4/3 ( As = 20/17 * Bs = 20/17 * 17/15 * Cs = 20/15 Cs

Lets assume to complete a 200 yards race A took time T , then

As=200/T or T = 200/As , in the same time C will cover X distance , so X = Cs * T (Distance = Speed * time)

Therefore X = Cs * 200/As ( from above we knw that As/Cs = 4/3 )

X = 200 / (As/Cs) = 200 / (4/3) = 150.

Thereby we can say that A will beat C in a 200 yards race by 50 yards.

Similarly we can get that B will beat D in a 200 yards race by 35 yards.

Hi punwish,

That's the correct answer. Yes, you are right this is a longer method to approach the question. I think the approach below is smarter one.

We can find out the continued ratios of all 4 players.

--A--:---B--:---C--:---D----
400 : 340
------:850 : 750
------:-----: 600 : 560
------------------------------------
400 : 340 : 750/850*340 : --
400 : 340 : 300 : 560/600*300
400 : 340 : 300 : 280

So. we can infer that A beats C by 100 yards in a 400 yard race, so it will beat C by 50 yards in a 200 yard race.

Similarly, we can infer that B beats D by 60 yards in 340 yard race, so it will beat D by (340-280)/340*200 = ~35 yards in a 200 yard race.

Meanwhile, don't forget to attend the SC session on Saturday. Please find the link below:

-Shalabh

Hi - I really like this method but i have a question

Given all the ratio's are equalized now (highlighted in purple font as continued ratio's) , i thought the green took place over the 400 yard race, not over a 340 yard race

Why is the green taking over a 340 yard race and not over a 400 yard race

All the ratio's are equlized and given we are starting from A to B which took place over a 400 yard race, i think B beat D over a 400 yard race and not over a 340 yard race

A 2 Part question &nbs [#permalink] 14 Nov 2017, 17:19
Display posts from previous: Sort by

A 2 Part question

Moderators: chetan2u, Bunuel

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.