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 350,000 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:

A new electric car company holds a limited-time sales event. [#permalink]
20 May 2013, 08:36

1

This post received KUDOS

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

95% (hard)

Question Stats:

39% (02:51) correct
61% (02:01) wrong based on 74 sessions

A new electric car company holds a limited-time sales event. On the first day, 3 cars are sold. On each subsequent day of the event, 3 more cars are sold than on the previous day. For how many days does the event last?

(1) If the event had lasted 2 more days, the average number of cars sold per day would have increased by 3.

(2) On exactly 9 days during the event, the number of cars for the day is a multiple of 9.

Re: A new electric car company holds a limited-time sales event. [#permalink]
20 May 2013, 09:11

1

This post received KUDOS

guerrero25 wrote:

A new electric car company holds a limited-time sales event. On the first day, 3 cars are sold. On each subsequent day of the event, 3 more cars are sold than on the previous day. For how many days does the event last?

(1) If the event had lasted 2 more days, the average number of cars sold per day would have increased by 3.

(2) On exactly 9 days during the event, the number of cars for the day is a multiple of 9.

OA to follow.

The question is a lil unclear, but If I were to go with sumthing, I'd go with [E].

For the car company, the sales for n days of sale would be in the set {3,6,9,.....3n} Hence total cars sold on n days would be 3n*(n+1)/2

With that in mind, Statement 1, says that if the event had lasted 2 more days, the average number of cars sold per day would have increased by 3. Hence the event lasted for n+2 days.

So Average of cars sold in n+2 days = 3(n+2)*(n+3)/2*(n+2) = (3n + 9)/2 Average of cars sold in n days = 3(n+1)/2 = (3n + 3)/2 Hence the difference is 3, which was calculated for all n. Hence it does not depend on the number of cars sold. Not sufficient.

Statement 2 says, On exactly 9 days during the event, the number of cars for the day is a multiple of 9. Assuming n = 9, the total number of cars sold = 3*9*10/2 = 15*9 a multiple of 9. Hence the statement is true, but does not specify if n is ultimately 9 or not. It simple states 'On exactly 9 days', and no mention is made if the event ended after the same.

The question is a little confusing. Probably the purpose of it was to do so! Nevertheless, Please verify my answer guerrero25! Hope its correct!

Re: A new electric car company holds a limited-time sales event. [#permalink]
20 May 2013, 09:14

2

This post received KUDOS

Expert's post

guerrero25 wrote:

A new electric car company holds a limited-time sales event. On the first day, 3 cars are sold. On each subsequent day of the event, 3 more cars are sold than on the previous day. For how many days does the event last?

(1) If the event had lasted 2 more days, the average number of cars sold per day would have increased by 3.

(2) On exactly 9 days during the event, the number of cars for the day is a multiple of 9.

The no of cars sold on the 1st day,2nd day,3rd day,4th day = 3,6,9,12 and so on.

Assuming the no of days the event lasted = 2, thus the average no of cars sold - (6+3)/2 = 4.5.Also, for the event to last for 2+2=4 days, the average no of cars sold = (3+6+9+12)/4 = 30/4 = 7.5-->7.5-4.5 =3.

Similarly if the event lasted for 1 day, average = 3/1 = 3.If the event lasted for 1+2 = 3 days, the average = 18/3 = 6 --> 6-3 = 3.Thus the relationship given in the F.S 1 is not sufficient.The relation provided will hold good, irrespective of the no of days involved for d and d+2 days.

From F.S 2, we know that the first time a multiple of 9 occurs is on the 3rd day. Thus, the no of cars sold were a multiple of 9 on 3rd,6th,9th... 27th day.However, it might so happen that some cars were sold on 28th day also, which is not a multiple of 9. Insufficient.

Taking both statements together, it is again insufficient. E. _________________

Re: A new electric car company holds a limited-time sales event. [#permalink]
20 May 2013, 09:49

2

This post received KUDOS

1

This post was BOOKMARKED

A new electric car company holds a limited-time sales event. On the first day, 3 cars are sold. On each subsequent day of the event, 3 more cars are sold than on the previous day. For how many days does the event last?

(1) If the event had lasted 2 more days, the average number of cars sold per day would have increased by 3. This is always true, and there is no need to say it... As my collegues correctly say

(2) On exactly 9 days during the event, the number of cars for the day is a multiple of 9. So the event lasted at least 81/3 days = 27, but it's not sufficient. If the event lasted 28 or 29 days this would still hold true

1+2) Because 1 do not add info to 2, the answer is E _________________

It is beyond a doubt that all our knowledge that begins with experience.

A new electric car company holds a limited-time sales event. [#permalink]
04 Sep 2013, 23:14

A new electric car company holds a limited-time sales event. On the first day, 3 cars are sold. On each subsequent day of the event, 3 more cars are sold than on the previous day. For how many days does the event last?

(1) If the event had lasted 2 more days, the average number of cars sold per day would have increased by 3.

(2) On exactly 9 days during the event, the number of cars for the day is a multiple of 9. _________________

Re: A new electric car company holds a limited-time sales event. [#permalink]
05 Sep 2013, 00:20

Expert's post

Stiv wrote:

A new electric car company holds a limited-time sales event. On the first day, 3 cars are sold. On each subsequent day of the event, 3 more cars are sold than on the previous day. For how many days does the event last?

(1) If the event had lasted 2 more days, the average number of cars sold per day would have increased by 3.

(2) On exactly 9 days during the event, the number of cars for the day is a multiple of 9.

Good news for globetrotting MBAs: travel can make you a better leader. A recent article I read espoused the benefits of traveling from a managerial perspective, stating that it...