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

It is currently 17 Feb 2019, 18:45

Close

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
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.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Free GMAT Algebra Webinar

     February 17, 2019

     February 17, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
  • Valentine's day SALE is on! 25% off.

     February 18, 2019

     February 18, 2019

     10:00 PM PST

     11:00 PM PST

    We don’t care what your relationship status this year - we love you just the way you are. AND we want you to crush the GMAT!

Anwar leaves home everyday at 4 p.m to pick his son from

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Intern
Intern
avatar
Joined: 02 Jun 2013
Posts: 18
Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post Updated on: 15 Jul 2013, 08:12
2
14
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

48% (03:16) correct 52% (03:18) wrong based on 132 sessions

HideShow timer Statistics

Anwar leaves home everyday at 4 p.m to pick his son from school and returns home at 6 p.m. One day, the school was over at 4 p.m and the son started walking home from school. Anwar, unaware of this, starts from home as usual and meets his son on the way and returns home with him 15 minutes early. If the speed of Anwar is 30 km\hr, find the speed of his son.

A. 15km/hr
B. 6 km/hr
C. 4.28 km/hr
D. 9 km/hr
E. 4.12 km/hr

Originally posted by abhishekkhosla on 15 Jul 2013, 07:59.
Last edited by Bunuel on 15 Jul 2013, 08:12, edited 1 time in total.
Renamed the topic and edited the question.
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52906
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 15 Jul 2013, 08:28
6
3
abhishekkhosla wrote:
Anwar leaves home everyday at 4 p.m to pick his son from school and returns home at 6 p.m. One day, the school was over at 4 p.m and the son started walking home from school. Anwar, unaware of this, starts from home as usual and meets his son on the way and returns home with him 15 minutes early. If the speed of Anwar is 30 km\hr, find the speed of his son.

A. 15km/hr
B. 6 km/hr
C. 4.28 km/hr
D. 9 km/hr
E. 4.12 km/hr


Anwar saved 15 minutes on round trip. So, he saved 7.5 minutes in one way --> he met his son at 4:52.5.

The distance covered by his son in 52.5 minutes is usually covered by Anwar in 7.5 minutes --> time in ration 7.5:52.5=1:7, thus the speed in ration 7:1 --> son's speed is 30/7=~4.28.

Answer: C.

Similar questions to practice:
each-day-a-man-meets-his-wife-at-the-train-station-after-93545.html
a-man-arrives-at-a-railway-station-90mins-before-the-time-at-100073.html
ray-who-lives-in-the-countryside-caught-a-train-for-home-ea-84295.html
mrs-robbins-started-half-an-hour-later-than-usual-for-market-104482.html
two-guns-were-fired-from-the-same-place-at-an-interval-of-93761.html

Hope it helps.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

General Discussion
Intern
Intern
avatar
Joined: 02 Jun 2013
Posts: 18
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 15 Jul 2013, 08:33
1
thanks a lot it is really helpful i need one help of your i have a big tabboo for Time distance and speed problem can you please give me some tips to improve it
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52906
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 15 Jul 2013, 08:44
1
abhishekkhosla wrote:
thanks a lot it is really helpful i need one help of your i have a big tabboo for Time distance and speed problem can you please give me some tips to improve it


Theory on Distance/Rate Problems: distance-speed-time-word-problems-made-easy-87481.html

DS Distance/Rate Problems to practice: search.php?search_id=tag&tag_id=44
PS Distance/Rate Problems to practice: search.php?search_id=tag&tag_id=64

Hope it helps.

BTW, the question you've posted has quite ambiguous wording, so I believe it's not from reliable GMAT source. My advice would be not to study from such sources.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Senior Manager
Senior Manager
User avatar
Joined: 13 May 2013
Posts: 422
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 03 Aug 2013, 12:00
Anwar leaves home everyday at 4 p.m to pick his son from school and returns home at 6 p.m. One day, the school was over at 4 p.m and the son started walking home from school. Anwar, unaware of this, starts from home as usual and meets his son on the way and returns home with him 15 minutes early. If the speed of Anwar is 30 km\hr, find the speed of his son.

The distance from home to school is 30 km. The round trip distance = 60 km. Because he returns home 15 minutes early, I thought it might be easier to break his trip up into 8 identical 15 minute blocks, each of which he traveled at 7.5 km/hour.

Because we are dealing with a round trip here, Anwar would have stopped 7.5 minutes short of the school. This means he traveled Distance=rate* time .5Km/hour*52.5 minutes or 26.25 KM. His son therefore traveled 3.75km/hour by the time he met his dad at 4:52.5. It took the son 52.5 minutes to travel 3.75 km. Because we are trying to find the son's rate per hour (i.e. 60 minutes) and we have his speed for 52.5 minutes it's best to convert to km/minute then multiply by 60 to get km/hour

3.75km/52.5 = .07 km/minute
.07km/minute*60 minutes = 4.28 km/hour.

Answer: C. 4.28 km/hr
Current Student
avatar
B
Joined: 23 May 2013
Posts: 186
Location: United States
Concentration: Technology, Healthcare
GMAT 1: 760 Q49 V45
GPA: 3.5
GMAT ToolKit User
Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 19 Feb 2015, 09:17
1
Since it normally takes him 2 hours round trip at 30 km/hr, we know that each leg is 30 km. Anwar's position at time t is 30t, while his son's is 30 - x*t.

\(30t = 30 - xt\)

\((30+x)t = 30\)

\(t = \frac{30}{30+x}\).

So they meet at time t. Since the total time is 2*t = 1 hour and 45 minutes, we know that:

\(\frac{60}{30+x} = \frac{7}{4}\)

\(240 = 210 + 7x\)

\(30 = 7x\)

\(x = \frac{30}{7} = 4.28\) km/hr.

Answer: C
Retired Moderator
avatar
P
Joined: 04 Aug 2016
Posts: 487
Location: India
Concentration: Leadership, Strategy
GPA: 4
WE: Engineering (Telecommunications)
Premium Member
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 22 Apr 2017, 09:53
1
1
Total Distance = Speed * Time = 30 * 2 = 60 kms

Let the speed of the child be x

Relative speed = 30 + x

Time = \(\frac{Distance}{Speed}\)

\(\frac{7}{4}\) = \(\frac{60}{(30+x)}\)

x= \(\frac{30}{7}\) = 4.28
VP
VP
avatar
P
Joined: 07 Dec 2014
Posts: 1157
Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 22 Apr 2017, 13:10
abhishekkhosla wrote:
Anwar leaves home everyday at 4 p.m to pick his son from school and returns home at 6 p.m. One day, the school was over at 4 p.m and the son started walking home from school. Anwar, unaware of this, starts from home as usual and meets his son on the way and returns home with him 15 minutes early. If the speed of Anwar is 30 km\hr, find the speed of his son.

A. 15km/hr
B. 6 km/hr
C. 4.28 km/hr
D. 9 km/hr
E. 4.12 km/hr


Anwar normally picks up son after driving 1 hour for 30 km
on this day he saves 15 minutes/120 minutes=1/8 time and distance
he drives only 7/8*1 hour before meeting son
he drives only 7/8*30 km before meeting son
therefore, son, who has started at the same time, walks the equivalent of 1/8 *30 km=3.75 km in 7/8 hour
3.75/(7/8)=4.28 km/hr
C
Director
Director
User avatar
S
Joined: 17 Dec 2012
Posts: 624
Location: India
Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 27 May 2017, 23:04
abhishekkhosla wrote:
Anwar leaves home everyday at 4 p.m to pick his son from school and returns home at 6 p.m. One day, the school was over at 4 p.m and the son started walking home from school. Anwar, unaware of this, starts from home as usual and meets his son on the way and returns home with him 15 minutes early. If the speed of Anwar is 30 km\hr, find the speed of his son.

A. 15km/hr
B. 6 km/hr
C. 4.28 km/hr
D. 9 km/hr
E. 4.12 km/hr


1. Let Anwar travel distance y and his son travel distance x when they meet.
2. Normally Anwar travels 2x + 2y distance, now he travels only 2y distance. He saves 15/2= 7.5 min in not traveling x distance or in other words he takes 7.5 min to travel x but we know he takes 120/2= 60 min to travel x+y.
3. The ratio of x and y is therefore 1:7.
4. So the speed is also in that ratio. Anwar's son speed is therefore 30/7 km/hr = 4.28 km/hr
_________________

Srinivasan Vaidyaraman
Sravna Holistic Solutions
http://www.sravnatestprep.com

Holistic and Systematic Approach

Intern
Intern
avatar
B
Status: hope for the best, prepare for the worst
Joined: 13 Dec 2015
Posts: 9
Location: Pakistan
Concentration: General Management, International Business
GPA: 3.19
Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 29 Jul 2017, 07:04
As for father
t=2 r=30 d=60
As for son
t-15min *R =60
(120-15)*R=60
R=34.28km/h

NOW relative speed traveling at same direction returning home
34.28-30=4.28km/h
Intern
Intern
avatar
B
Joined: 04 Oct 2016
Posts: 17
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 13 Feb 2019, 18:48
warriorguy wrote:
Total Distance = Speed * Time = 30 * 2 = 60 kms

Let the speed of the child be x

Relative speed = 30 + x

Time = \(\frac{Distance}{Speed}\)

\(\frac{7}{4}\) = \(\frac{60}{(30+x)}\)

x= \(\frac{30}{7}\) = 4.28


Can someone please explain, how is time 7/4?
Manager
Manager
User avatar
B
Joined: 07 Aug 2017
Posts: 60
Location: India
GPA: 4
WE: Information Technology (Consulting)
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 14 Feb 2019, 07:00
mischiefmanaged wrote:
warriorguy wrote:
Total Distance = Speed * Time = 30 * 2 = 60 kms

Let the speed of the child be x

Relative speed = 30 + x

Time = \(\frac{Distance}{Speed}\)

\(\frac{7}{4}\) = \(\frac{60}{(30+x)}\)

x= \(\frac{30}{7}\) = 4.28


Can someone please explain, how is time 7/4?



Normally it takes 120 mins for Anwar but this time it took 105 mins that is 7/4 hours.

However, as per my understanding the equation should be as below in the context of relative speed.

\(t=\frac{d}{s}\)

here t is the time at which Anwar meets his son, d is the distance between them and s is their relative speed, i.e, speed of Anwar plus his son's
Normally, it takes 2 hours for Anwar with the speed of 30 km/hr to do a round trip. From this it can be derived that round trip distance is 60 km and the distance between anwar and his son d =30 km
When it took 105 mins for Anwar to complete his trip, he met his son at 105/2= 52.5 mins = 7/8 hrs
Considering the speed of Anwar's son as x, the relative speed is 30 + x

The above equation becomes,
\(\frac{7}{8}=\frac{30}{(30+x)}\)
\(x=30/7=4.28 km/hr\)

-----------------------------------------------------------------------------
Kudos if helpful!
Intern
Intern
avatar
B
Joined: 23 Aug 2017
Posts: 40
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 14 Feb 2019, 23:56
chetan2u VeritasKarishma Bunuel
The son starts at 4 PM , meets Anwar somewhere in the return journey and returns back 15 min earlier than 6PM...ie at 5.45 PM...So it means the son completed the return journey(30km) in 1hr 45 mins....then his speed should be 30/1.75 ...

Can someone please elaborate where am I wrong?
Manager
Manager
User avatar
B
Joined: 07 Aug 2017
Posts: 60
Location: India
GPA: 4
WE: Information Technology (Consulting)
Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 15 Feb 2019, 00:33
1
Debashis Roy wrote:
chetan2u VeritasKarishma Bunuel
The son starts at 4 PM , meets Anwar somewhere in the return journey and returns back 15 min earlier than 6PM...ie at 5.45 PM...So it means the son completed the return journey(30km) in 1hr 45 mins....then his speed should be 30/1.75 ...

Can someone please elaborate where am I wrong?



When you say "30/1.75", you are considering that the distance travelled by son in time 1.75 is 30 km. However, son travelled only the distance d till he met Anwar. After he met Anwar, they returned with the speed of 30 km/hr, which is the speed of Anwar and the time changed accordingly.

It should be speed of son = ds/ts

Ds = 30 - Da = 30 - 26.25 = 3.75 km
ts = time taken by Anwar/2 = 1.75/2 = 0.875 hrs,

speed of son = 3.75/0.875 = 4.28 km/hr

-----------------------------
Kudos if helpful!
Intern
Intern
avatar
B
Joined: 23 Aug 2017
Posts: 40
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 15 Feb 2019, 01:08
where from are u getting Da = 26.25?
Manager
Manager
User avatar
B
Joined: 07 Aug 2017
Posts: 60
Location: India
GPA: 4
WE: Information Technology (Consulting)
Re: Anwar leaves home everyday at 4 p.m to pick his son from  [#permalink]

Show Tags

New post 15 Feb 2019, 01:14
Debashis Roy wrote:
where from are u getting Da = 26.25?


Da is the distance covered by Anwar that is normally 60 kms. But on this specific day, Anwar travelled for 105 mins(7/4 hrs) and at 30 km/hr. So distance covered by Anwar on this day is D = 30*7/4= 52.5 km.
But 52.5 is round trip distance(home to school to home), so one way(home to school) is 52.5/2 = 26.25 km. In simple words, the distance between Anwar and his son is 30 km but on this day Anwar travelled only for 26.25 km because his son already started and covered 3.75 km by walk.
GMAT Club Bot
Re: Anwar leaves home everyday at 4 p.m to pick his son from   [#permalink] 15 Feb 2019, 01:14
Display posts from previous: Sort by

Anwar leaves home everyday at 4 p.m to pick his son from

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.