It is currently 22 Oct 2017, 00:08

### 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 June
Open Detailed Calendar

# M16#8

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Forum Moderator
Status: mission completed!
Joined: 02 Jul 2009
Posts: 1391

Kudos [?]: 952 [0], given: 621

GPA: 3.77

### Show Tags

12 Nov 2010, 13:05
hi guys

My respect to that person who created this question.

Here is very nice questions, which shows how tricky may be GMAT questions. Professionals who create such questions are also phycometrists - (or smth like that). They are sycologists who know how the logical flow of an ordinary person works and what are the gaps.
Most of you have realised that in 1) In the first 2 hours the bus.... - they talk about a part of total time
in 2) The average speed of the bus for the first half of the distance was - they talk about a part of total distance.

you want to solve it rapidly you have heard about half of and your brain does not want to care about this anymore.

This question may pretend to become one of my favorite questions.
_________________

Audaces fortuna juvat!

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 952 [0], given: 621

Intern
Joined: 18 Jan 2010
Posts: 4

Kudos [?]: [0], given: 0

Schools: Kellogg

### Show Tags

02 Feb 2011, 13:01
It took the bus 4 hours to get from town A to town B. What was the average speed of the bus for the trip?

1. In the first 2 hours the bus covered 100 miles
2. The average speed of the bus for the first half of the distance was twice its speed for the second half

Statement 1: This tells me that during the first 2 hours, the speed of the bus is 50mph.

Statement 2: This is not sufficient because I do not know the average speed of the bus during the first half of the distance or the second half of the distance.

Statement 3: We should NOT assume that during the first 2 hours of the trip, the bus has covered the first half of the distance. We do not know the total distance of the trip. Both statements will not give us the answer.

My answer is E. Very tricky C-trap question.

Kudos [?]: [0], given: 0

Manager
Joined: 16 Sep 2010
Posts: 219

Kudos [?]: 135 [0], given: 2

Location: United States
Concentration: Finance, Real Estate
GMAT 1: 740 Q48 V42

### Show Tags

14 Feb 2011, 22:11
E. No where in the question does it state the total distance. You can be fooled into thinking C by assuming that 100 miles is half the distance. However it never states this.

Kudos [?]: 135 [0], given: 2

Math Expert
Joined: 02 Sep 2009
Posts: 41889

Kudos [?]: 129207 [0], given: 12196

### Show Tags

04 Feb 2012, 06:59
This question is also discussed here: if-it-took-a-bus-4-hours-to-get-from-town-a-to-town-b-what-102361.html

There is a following trick in the question:

If (2) were: The constant speed of the bus for the first half of the distance was twice its constant speed for the second half.

Then for (1)+(2) we would have: $$s_1*\frac{4}{3}+\frac{s_1}{2}*(2-\frac{4}{3})=100$$ --> we can find $$s_1$$ so we can find $$d$$ ($$d=2*s_1*\frac{4}{3}$$).

BUT: as it is now, we don't know whether the average speed after first $$\frac{4}{3}$$ hours till 2 hours from the start was $$\frac{s_1}{2}$$ or less or more, we just know that the average speed from first $$\frac{4}{3}$$ hours till 4 hours from the start was $$\frac{s_1}{2}$$.

Hence the answer is E.

Hope it's clear.
_________________

Kudos [?]: 129207 [0], given: 12196

Manager
Status: MBA Aspirant
Joined: 12 Jun 2010
Posts: 172

Kudos [?]: 98 [0], given: 1

Location: India
Concentration: Finance, International Business
WE: Information Technology (Investment Banking)

### Show Tags

06 Feb 2012, 03:53
The answer is E.
For solving this question we ought to know the distance between the towns A & B. Since none of the statements provide that so the answer is E.

Kudos [?]: 98 [0], given: 1

Manager
Joined: 10 Jan 2011
Posts: 232

Kudos [?]: 81 [0], given: 25

Location: India
GMAT Date: 07-16-2012
GPA: 3.4
WE: Consulting (Consulting)

### Show Tags

08 Feb 2013, 03:56
Lets assume total distance = 2d.

we need to calculate 2d/4 = average speed for entire trip.

statement 1: tells us that bus travel 50MPH for first 2 hrs... clearly not sufficient.

statement 2: let 2v be the speed for first half, then v be the speed for second half.
d/2v + d/v = 4
d/4 = 2vsqure/3v
d/4 = 2/3 v.
as we don't know v. statement 2 is not sufficient.

combining st1 and 2. we can not calculate v. as 50 MPH given for first 2 hr and not first half of the journey.

_________________

-------Analyze why option A in SC wrong-------

Kudos [?]: 81 [0], given: 25

Intern
Joined: 06 May 2013
Posts: 8

Kudos [?]: [0], given: 0

### Show Tags

22 Jan 2014, 14:03
OA should be E.
There is no way we can calculate the Average speed.
From 1) we cannot say that 100 miles is half a distance. It might possible that 100 miles is only the one third of the distance and bus covers rest 2/3 distance in another 2 hrs. Making total of 4 hrs of total journey.
From 2) only gives the ratio of speeds for the first half to the second half.

Even using both these we cannot find the average speed.

Kudos [?]: [0], given: 0

Manager
Joined: 20 Oct 2013
Posts: 75

Kudos [?]: 12 [0], given: 15

Location: United States
Concentration: General Management, Real Estate

### Show Tags

20 Apr 2014, 08:45
1) No relation is drawn between the trip A-B and 100 miles -> insufficient
2) We need a specific figure for the ans -> also insufficient
Combine 2 stats:
From 2), the time spent on the first half of the trip is 1/2 that spent on the 2nd half => time spent on 1st half = 4/3hrs
-> from 1): 2a*4/3+a*2/3=100 -> a=30 -> average speed on the trip = [60*4/3+30*8/3]/4=40

Choose C

Kudos [?]: 12 [0], given: 15

Re: M16#8   [#permalink] 20 Apr 2014, 08:45

Go to page   Previous    1   2   [ 28 posts ]

Display posts from previous: Sort by

# M16#8

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

Moderator: 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®.