Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 27 May 2017, 02:25

### 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

# If a certain bus line's ridership in July was 3/5 of its

Author Message
TAGS:

### Hide Tags

Manager
Joined: 28 May 2009
Posts: 156
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE: Information Technology (Consulting)
Followers: 8

Kudos [?]: 233 [0], given: 91

If a certain bus line's ridership in July was 3/5 of its [#permalink]

### Show Tags

31 Jan 2013, 17:45
00:00

Difficulty:

15% (low)

Question Stats:

77% (02:33) correct 23% (02:13) wrong based on 124 sessions

### HideShow timer Statistics

If a certain bus line's ridership in July was $$\frac{3}{5}$$ of its ridership in June, and its ridership in August was $$\frac{1}{3}$$ of its ridership in July, then the bus line's ridership in June was how many times the average (arithmetic mean) of its ridership in July and August?

(A) $$\frac{1}{2}$$

(B) $$1\frac{2}{3}$$

(C) $$2$$

(D) $$2\frac{1}{2}$$

(E) $$5$$

Relatively easy problem. For some reason I'm getting different answer when I tried using variables and when I tried using numbers. I think my variable approach is wrong, can someone explain using variable approach?

Source: Sackmann's 1800 set
[Reveal] Spoiler: OA

_________________
VP
Status: Been a long time guys...
Joined: 03 Feb 2011
Posts: 1381
Location: United States (NY)
Concentration: Finance, Marketing
GPA: 3.75
Followers: 178

Kudos [?]: 1464 [1] , given: 62

Re: If a certain bus line's ridership in July was 3/5 of its [#permalink]

### Show Tags

31 Jan 2013, 20:40
1
KUDOS
megafan wrote:
If a certain bus line's ridership in July was $$\frac{3}{5}$$ of its ridership in June, and its ridership in August was $$\frac{1}{3}$$ of its ridership in July, then the bus line's ridership in June was how many times the average (arithmetic mean) of its ridership in July and August?

(A) $$\frac{1}{2}$$

(B) $$1\frac{2}{3}$$

(C) $$2$$

(D) $$2\frac{1}{2}$$

(E) $$5$$

Relatively easy problem. For some reason I'm getting different answer when I tried using variables and when I tried using numbers. I think my variable approach is wrong, can someone explain using variable approach?

Source: Sackmann's 1800 set

Let the ridership in June be x. Then in july, the ridership would be 3x/5 and thereby in August be x/5. The mean of riderships in the month of July and August would be 2x/5 (no need to calculate, just pick the in between number).
Now the question asks : the ridership in June is how many times that of the average that we just found.
Therefore x/(2x/5)=5/2.
Hope that helps.
_________________
Manager
Joined: 28 May 2009
Posts: 156
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE: Information Technology (Consulting)
Followers: 8

Kudos [?]: 233 [0], given: 91

Re: If a certain bus line's ridership in July was 3/5 of its [#permalink]

### Show Tags

31 Jan 2013, 20:50
Thanks Marcab. I made a silly mistake when taking the average with the reciprocal and arrived at 8x/5, which of course should be 2x/5. Anyway, I tend to make these silly mistakes once in a while, especially when I am doing the Math in my head. I will practice to make good use of my scratch paper from now.
_________________
Manager
Joined: 28 May 2009
Posts: 156
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE: Information Technology (Consulting)
Followers: 8

Kudos [?]: 233 [0], given: 91

Re: If a certain bus line's ridership in July was 3/5 of its [#permalink]

### Show Tags

31 Jan 2013, 20:50
Thanks Marcab. I made a silly mistake when taking the average with the reciprocal and arrived at 8x/5, which of course should be 2x/5. Anyway, I tend to make these silly mistakes once in a while, especially when I am doing the Math in my head. I will practice to make good use of my scratch paper from now.
_________________
VP
Status: Been a long time guys...
Joined: 03 Feb 2011
Posts: 1381
Location: United States (NY)
Concentration: Finance, Marketing
GPA: 3.75
Followers: 178

Kudos [?]: 1464 [0], given: 62

Re: If a certain bus line's ridership in July was 3/5 of its [#permalink]

### Show Tags

31 Jan 2013, 20:53
Well, if you commit a mistake then try to use number picking. On the test, the last thing you would want is being stuck to a problem.
_________________
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7377
Location: Pune, India
Followers: 2288

Kudos [?]: 15130 [3] , given: 224

Re: If a certain bus line's ridership in July was 3/5 of its [#permalink]

### Show Tags

31 Jan 2013, 21:25
3
KUDOS
Expert's post
megafan wrote:
Thanks Marcab. I made a silly mistake when taking the average with the reciprocal and arrived at 8x/5, which of course should be 2x/5. Anyway, I tend to make these silly mistakes once in a while, especially when I am doing the Math in my head. I will practice to make good use of my scratch paper from now.

Bad idea! Try to stick to doing the calculations in your mind till it becomes second nature. Then you will feel that writing down is too cumbersome. Initially, there will be more errors but later on, you will get very efficient.
Also, if trying to solve orally, making equations mentally isn't the appropriate approach. Take numbers instead:

So there is a 5 and a 3 in the denominator.
Say ridership in June = 15
Ridership in July = (3/5)*15 = 9
Ridership in Aug = (1/3)*9 = 3
Avg ridership in July and Aug = 6

Required answer = 15/6 = 5/2
Now this can be easily done in your mind. You can write 15, 9, 3 and 6 on your scratch pad if you wish but that should be just to ensure that you don't lose focus.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Re: If a certain bus line's ridership in July was 3/5 of its   [#permalink] 31 Jan 2013, 21:25
Similar topics Replies Last post
Similar
Topics:
1 On a certain bus, one-fourth of the children are boys that are wearing 6 29 Dec 2016, 11:29
1 Harriet planned to complete a certain task on Wednesday, January 1, bu 6 22 Apr 2017, 04:25
2 A total of x tourists were transported by bus to a certain museum. If 3 28 Nov 2015, 21:03
9 A bus traveled from its depot to its destination at an average speed 12 19 Jul 2015, 13:04
14 The number of passengers on a certain bus at any given time is given 5 10 Jan 2017, 19:45
Display posts from previous: Sort by