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

 It is currently 18 Aug 2018, 03:55

### 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

# Two person start walking on a road that diverge at angle of 120

Author Message
TAGS:

### Hide Tags

Manager
Joined: 01 Jun 2015
Posts: 230
Location: India
GMAT 1: 620 Q48 V26
Two person start walking on a road that diverge at angle of 120  [#permalink]

### Show Tags

12 May 2016, 05:01
3
00:00

Difficulty:

35% (medium)

Question Stats:

73% (02:56) correct 27% (02:28) wrong based on 30 sessions

### HideShow timer Statistics

Two person start walking on a road that diverge at angle of 120 degree.If they walk at the rate of 2kmph and 3 3kmph relatively, then find the distance between them after 4 hours or find the value of c as given in the image attached below.

A.5
B. 4√19
C.7
D. 8√19
E. √19

Attachments

GEOMETRY3.jpg [ 8.75 KiB | Viewed 1227 times ]

Manager
Joined: 12 Jun 2015
Posts: 79
Two person start walking on a road that diverge at angle of 120  [#permalink]

### Show Tags

Updated on: 12 May 2016, 06:32
hi techiesam,

can you please check if the question is correct, specifically whether one of the speeds is 3 kmph or 33 kmph
Also,
you can simply use the following formula for cos x to get your answer :

c^2 = a^2 + b^2 - 2abcos(120)
= a^2 + b^2 - 2ab(-1/2)
= a^2 + b^2 + ab

Originally posted by ronny123 on 12 May 2016, 05:52.
Last edited by ronny123 on 12 May 2016, 06:32, edited 1 time in total.
Math Expert
Joined: 02 Aug 2009
Posts: 6548
Two person start walking on a road that diverge at angle of 120  [#permalink]

### Show Tags

12 May 2016, 06:16
1
1
techiesam wrote:
Two person start walking on a road that diverge at angle of 120 degree.If they walk at the rate of 2kmph and 3 3kmph relatively, then find the distance between them after 4 hours or find the value of c as given in the image attached below.

A.5
B. 4√19
C.7
D. 8√19
E. √19

hi,

Trignometry is NOT tested in GMAT so there has to be another solution..
SEE att image..
Draw an altitude from A to BC extende at D..
Triangle ACD is a right angle triangle, whose HYP is 2*4..
rest sides are CD-4, opp 30 degree and AD - $$4\sqrt{3}$$, opp 60 degree..

c is hyp..
BD = 3*4 + 4 = 16 and AD = $$4\sqrt{3}$$..
HYp = AC = $$\sqrt{16^2+(4*Sq Root 3})^2$$ = $$\sqrt{304}$$ = $$4\sqrt{19}$$
B
Attachments

IMG_5618.JPG [ 1.75 MiB | Viewed 1196 times ]

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor

Manager
Joined: 12 Jun 2015
Posts: 79
Re: Two person start walking on a road that diverge at angle of 120  [#permalink]

### Show Tags

12 May 2016, 06:31
chetan2u wrote:
techiesam wrote:
Two person start walking on a road that diverge at angle of 120 degree.If they walk at the rate of 2kmph and 3 3kmph relatively, then find the distance between them after 4 hours or find the value of c as given in the image attached below.

A.5
B. 4√19
C.7
D. 8√19
E. √19

hi,

Trignometry is NOT tested in GMAT so there has to be another solution..
SEE att image..
Draw an altitude from A to BC extende at D..
Triangle ACD is a right angle triangle, whose HYP is 2*4..
rest sides are CD-4, opp 30 degree and AD - $$4\sqrt{3}$$, opp 60 degree..

c is hyp..
BD = 3*4 + 4 = 16 and AD = $$4\sqrt{3}$$..
HYp = AC = $$\sqrt{16^2+(4*Sq Root 3})^2$$ = $$\sqrt{304}$$ = $$4\sqrt{19}$$
B

hi,

Don't be offended but isn't the maths inherent to subject correct ?

if you use c^2 = a^2 + b^2 - 2abcos(120)
= a^2 + b^2 - 2ab(-1/2)
= a^2 + b^2 + ab

a = 2 x 4 = 8
b = 3 x 4 = 12
Putting these values,
c^2 = 8^2 + 12^2 + (8)(12)
= 64 +144 + 96
= 304
c = 4√‾19

Saying Trigo isn't tested on the GMAT isn't changing the solution, my friend
Again, no offense meant.
Math Expert
Joined: 02 Aug 2009
Posts: 6548
Re: Two person start walking on a road that diverge at angle of 120  [#permalink]

### Show Tags

12 May 2016, 06:37
ronny123 wrote:
chetan2u wrote:
techiesam wrote:
Two person start walking on a road that diverge at angle of 120 degree.If they walk at the rate of 2kmph and 3 3kmph relatively, then find the distance between them after 4 hours or find the value of c as given in the image attached below.

A.5
B. 4√19
C.7
D. 8√19
E. √19

hi,

Trignometry is NOT tested in GMAT so there has to be another solution..
SEE att image..
Draw an altitude from A to BC extende at D..
Triangle ACD is a right angle triangle, whose HYP is 2*4..
rest sides are CD-4, opp 30 degree and AD - $$4\sqrt{3}$$, opp 60 degree..

c is hyp..
BD = 3*4 + 4 = 16 and AD = $$4\sqrt{3}$$..
HYp = AC = $$\sqrt{16^2+(4*Sq Root 3})^2$$ = $$\sqrt{304}$$ = $$4\sqrt{19}$$
B

hi,

Don't be offended but isn't the maths inherent to subject correct ?

if you use c^2 = a^2 + b^2 - 2abcos(120)
= a^2 + b^2 - 2ab(-1/2)
= a^2 + b^2 + ab

a = 2 x 4 = 8
b = 3 x 4 = 12
Putting these values,
c^2 = 8^2 + 12^2 + (8)(12)
= 64 +144 + 96
= 304
c = 4√‾19

Saying Trigo isn't tested on the GMAT isn't changing the solution, my friend
Again, no offense meant.

Hi,
It is not meant for you ..
It is for people who are preparing for GMAT so that they do not get into the area where it is NOT required..
You are most welcome to learn anything being tested or not,
BUT people who are interested in just GMAT should not go away with thought that they have to do trignometry to do this Q..

I don't require to take offence or offend you, I am giving the WAY one should think about this solution
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor

Non-Human User
Joined: 09 Sep 2013
Posts: 7755
Re: Two person start walking on a road that diverge at angle of 120  [#permalink]

### Show Tags

28 Jul 2018, 02:47
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: Two person start walking on a road that diverge at angle of 120 &nbs [#permalink] 28 Jul 2018, 02:47
Display posts from previous: Sort by

# Events & Promotions

 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®.