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

 It is currently 16 Sep 2019, 21:50

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

Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B

Author Message
TAGS:

Hide Tags

Intern
Joined: 30 Mar 2019
Posts: 5
Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B  [#permalink]

Show Tags

20 Aug 2019, 12:12
1
00:00

Difficulty:

55% (hard)

Question Stats:

66% (02:48) correct 34% (03:30) wrong based on 35 sessions

HideShow timer Statistics

Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B travelling at 90km/ he also leaves Mumbai for Delhi at 9 PM. Train C leaves Delhi for Mumbai at 9PM. If all the trains meet at the same time between Mumbai and Delhi, what is the speed of train C if the distance between Delhi and Mumbai is 1260 kms?

A 120 km/hr
B 135 km/he
C 240 km/ hr
D 105 km/ hr
E 90 km/ hr
Senior Manager
Joined: 29 Jun 2019
Posts: 302
Re: Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B  [#permalink]

Show Tags

20 Aug 2019, 13:41
90(t-3)=60t
30t=270
t=9,60×9=540
So trains A and B, travel 540 kms of 1260 distance between Delhi and Numbai.
1260-540=720
Because C travels at 9,so
720=6v ==》v=120
Option A

Posted from my mobile device
_________________
Always waiting
Manager
Joined: 20 Jul 2012
Posts: 118
GMAT 1: 650 Q47 V33
Re: Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B  [#permalink]

Show Tags

20 Aug 2019, 14:04
1
shubhigandhi10 wrote:
Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B travelling at 90km/ he also leaves Mumbai for Delhi at 9 PM. Train C leaves Delhi for Mumbai at 9PM. If all the trains meet at the same time between Mumbai and Delhi, what is the speed of train C if the distance between Delhi and Mumbai is 1260 kms?

A 120 km/hr
B 135 km/he
C 240 km/ hr
D 105 km/ hr
E 90 km/ hr

Posted from my mobile device

If at distance d from Mumbai they meet and s speed of train C

d/60 = d/90+3 = (1260-d)/s + 3

From 1st eqn, d = 540 km.
so 540/60 = (1260-540)/s +3
=> s = 720/6 = 120kmph
Director
Status: Manager
Joined: 27 Oct 2018
Posts: 602
Location: Egypt
GPA: 3.67
WE: Pharmaceuticals (Health Care)
Re: Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B  [#permalink]

Show Tags

20 Aug 2019, 17:01
2
1
First, we shall find when & where will B catch up to A:
As A moved 3 hours earlier, the distance between them was 60*3 = 180 km
The time needed by B to catch up to A = $$\frac{180}{90-60} = 6$$ hours
In 6 hours, Train B will have traveled 90*6 = 540 km

So the left distance that Train C should have traveled to meed A & B = 1260 - 540 = 720 km

As train B & C started traveling at the same time, C must have traveled for 6 hours same as B.
so the speed of C = $$\frac{720}{6}$$ = 120 km/h
_________________
Thanks for KUDOS
SVP
Joined: 03 Jun 2019
Posts: 1500
Location: India
Re: Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B  [#permalink]

Show Tags

20 Aug 2019, 22:11
shubhigandhi10 wrote:
Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B travelling at 90km/ he also leaves Mumbai for Delhi at 9 PM. Train C leaves Delhi for Mumbai at 9PM. If all the trains meet at the same time between Mumbai and Delhi, what is the speed of train C if the distance between Delhi and Mumbai is 1260 kms?

A 120 km/hr
B 135 km/he
C 240 km/ hr
D 105 km/ hr
E 90 km/ hr

Given:
1. Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM.
2. Train B travelling at 90km/ he also leaves Mumbai for Delhi at 9 PM.
3. Train C leaves Delhi for Mumbai at 9PM.
4. All the trains meet at the same time between Mumbai and Delhi
5. The distance between Delhi and Mumbai is 1260 kms

Asked: What is the speed of train C ?

Let the speed of train C be x.

1. Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM.
2. Train B travelling at 90km/ he also leaves Mumbai for Delhi at 9 PM.

Train A travel from 6PM to 9PM = 60 *3 = 180 km

4. All the trains meet at the same time between Mumbai and Delhi
Train A & Train B meet at = 180/(90-60) = 6 hours after 9PM
Train B travels = 90*6 = 540 km from Mumbai to Delhi at the time of meeting.

5. The distance between Delhi and Mumbai is 1260 kms
Train distance travelled by train C from Delhi to Mumbai = 1260 - 540 = 720 km
Time taken by train C = 6 hours
Speed of train C = 720/6 = 120 kmh

IMO A
_________________
"Success is not final; failure is not fatal: It is the courage to continue that counts."

Please provide kudos if you like my post. Kudos encourage active discussions.

My GMAT Resources: -

Efficient Learning
All you need to know about GMAT quant

Tele: +91-11-40396815
Mobile : +91-9910661622
E-mail : kinshook.chaturvedi@gmail.com
Re: Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 PM. Train B   [#permalink] 20 Aug 2019, 22:11
Display posts from previous: Sort by