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 Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Two guns were fired from the same place at an interval of 10 [#permalink]

Show Tags

06 May 2010, 04:34

2

This post received KUDOS

24

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

95% (hard)

Question Stats:

47% (03:19) correct
53% (03:34) wrong based on 196 sessions

HideShow timer Statistics

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

A. 19.8 B. 58.6 C. 59.4 D. 111.8

Is this question too tough for GMAT level? or it can be considered for GMAT? I took 4 minutes to solve this.

Do let me know how log does it take for you and also if this is worth getting in GMAT.

Is this question too tough for GMAT level? or it can be considered for GMAT? I took 4 minutes to solve this.

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

a) 19.8 b) 58.6 c) 59.4 d) 111.8

Do let me know how log does it take for you and also if this is worth getting in GMAT.

In 30 sec sound covers the same distance as train in 10 min.

In 30 seconds sound covers 330*30=9900m=9.9 km, --> hence in 10 minutes train covers 9.9 km --> in 1 hr train covers 9.9*6 km= 59.4 km.

Re: Is this question too tough for GMAT level? [#permalink]

Show Tags

06 May 2010, 08:36

1

This post was BOOKMARKED

Bunuel wrote:

amitjash wrote:

Is this question too tough for GMAT level? or it can be considered for GMAT? I took 4 minutes to solve this.

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

a) 19.8 b) 58.6 c) 59.4 d) 111.8

Do let me know how log does it take for you and also if this is worth getting in GMAT.

In 30 sec sound covers the same distance as train in 10 min.

In 30 seconds sound covers 330*30=9900m=9.9 km, --> hence in 10 minutes train covers 9.9 km --> in 1 hr train covers 9.9*6 km= 59.4 km.

Answer: C.

I guess for GMAT it's 700+ question.

Hi Bunuel, could you please explain more about the way you think this problem. Thanks!

Is this question too tough for GMAT level? or it can be considered for GMAT? I took 4 minutes to solve this.

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

a) 19.8 b) 58.6 c) 59.4 d) 111.8

Do let me know how log does it take for you and also if this is worth getting in GMAT.

In 30 sec sound covers the same distance as train in 10 min.

In 30 seconds sound covers 330*30=9900m=9.9 km, --> hence in 10 minutes train covers 9.9 km --> in 1 hr train covers 9.9*6 km= 59.4 km.

Answer: C.

I guess for GMAT it's 700+ question.

Hi Bunuel, could you please explain more about the way you think this problem. Thanks!

If the person were static he would hear ("meet") the sound in 10.5 minutes, but he heard ("met") the sound in 10 minutes, and that's because during these 10 minutes the person was moving towards the sound. Thus these 10 minutes of person moving "saved" the sound its 0.5 minutes of moving.

OR: let's say (imagine) the distance between the shooting point and person when the second shot was made was \(d\). We are told that this distance would be covered in 10.5 minutes if person were static: \(d=10.5s\) (\(s\) speed of sound).

But because person was was moving towards the sound they "met" in 10 minutes, which means that the distance \(d\) was covered in 10 minutes at their combined speed. Their combined speed was \(s+t\) (\(t\) the speed of person/train): \(d=10(s+t)\).

Re: Is this question too tough for GMAT level? [#permalink]

Show Tags

11 Mar 2012, 05:20

amitjash wrote:

Is this question too tough for GMAT level? or it can be considered for GMAT? I took 4 minutes to solve this.

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

a) 19.8 b) 58.6 c) 59.4 d) 111.8

Do let me know how log does it take for you and also if this is worth getting in GMAT.

Let the time when first bullet was heard by the person be t0 = 0 mins Now train moves with a certain speed x m/s. Another shot was fired after 10m 30s, since the train was already moving in towards the place where shots were fired, it could here it little earler i.e., 10 mins. In 10 mins the train travelled certain distance too. Also, had the train been stationary, it would have heard the sound of the shot after 10mins 30 seconds only.

It thus implies that distance travelled by train in 10 mins is equal to distance travelled by bullet in 30s. Hence the equation

330 m/s * 30s = 600s * x m/s x = 33/2 m/s => 59.4 kmph

Re: Two guns were fired from the same place at an interval of 10 [#permalink]

Show Tags

04 Aug 2013, 12:05

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

I'm not entirely sure I understand the wording. Are they trying to say that gun 1 was fired at T=0 then gun 2 fired at T=10:30?

If that's the case, the person in the approaching train moved towards the two guns enough so that instead of the sound taking 10 minutes & 30 seconds to reach him, it took just 10 minutes. In other words, he moved towards the guns enough so it takes 30 seconds less for the sound to travel to him.

Time it takes the sound to reach him originally: 10:30 = 630 seconds * 330 m/seconds = 207,900 meters Time it takes the sound to reach him after he has moved towards the guns: 10:00 = 600 seconds * 330 m/seconds = 198,000

Difference = 9900m.

So the train moved 9900m closer to the guns in 10 minutes time. Therefore at a constant rate he would have moved 9900*10/1*6/1hour = 9900*60 = 59400m/hour = 59.4 km/h

Re: Two guns were fired from the same place at an interval of 10 [#permalink]

Show Tags

21 Aug 2014, 05:44

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 guns were fired from the same place at an interval of 10 [#permalink]

Show Tags

02 Sep 2015, 00:32

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 guns were fired from the same place at an interval of 10 [#permalink]

Show Tags

09 Jul 2016, 03:52

I was just going through the explanations, but what I dont understand is that if the shot was fired 10.5 mins after the first one, how can the man hear the second shot even before it was shot!

Bunuel wrote:

Is this question too tough for GMAT level? or it can be considered for GMAT? I took 4 minutes to solve this.

Two guns were fired from the same place at an interval of 10 minustes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of train (in km/hr), supposing that sound travels at 330m/s is:

a) 19.8 b) 58.6 c) 59.4 d) 111.8

Do let me know how log does it take for you and also if this is worth getting in GMAT.

In 30 sec sound covers the same distance as train in 10 min.

In 30 seconds sound covers 330*30=9900m=9.9 km, --> hence in 10 minutes train covers 9.9 km --> in 1 hr train covers 9.9*6 km= 59.4 km.

Answer: C.

I guess for GMAT it's 700+ question.[/quote] Hi Bunuel, could you please explain more about the way you think this problem. Thanks![/quote]

If the person were static he would hear ("meet") the sound in 10.5 minutes, but he heard ("met") the sound in 10 minutes, and that's because during these 10 minutes the person was moving towards the sound. Thus these 10 minutes of person moving "saved" the sound its 0.5 minutes of moving.

OR: let's say (imagine) the distance between the shooting point and person when the second shot was made was \(d\). We are told that this distance would be covered in 10.5 minutes if person were static: \(d=10.5s\) (\(s\) speed of sound).

But because person was was moving towards the sound they "met" in 10 minutes, which means that the distance \(d\) was covered in 10 minutes at their combined speed. Their combined speed was \(s+t\) (\(t\) the speed of person/train): \(d=10(s+t)\).

\(d=10.5s=10(s+t)\) --> \(0.5s=10t\).

Hope it helps.[/quote]

gmatclubot

Re: Two guns were fired from the same place at an interval of 10
[#permalink]
09 Jul 2016, 03:52

Happy New Year everyone! Before I get started on this post, and well, restarted on this blog in general, I wanted to mention something. For the past several months...

It’s quickly approaching two years since I last wrote anything on this blog. A lot has happened since then. When I last posted, I had just gotten back from...

Happy 2017! Here is another update, 7 months later. With this pace I might add only one more post before the end of the GSB! However, I promised that...