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 500,000 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:

In 1995 Division A of company had 4850 customers. If there [#permalink]

Show Tags

20 Aug 2010, 00:58

3

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

65% (hard)

Question Stats:

49% (01:35) correct 51% (01:30) wrong based on 131 sessions

HideShow timer Statistics

In 1995 Division A of company had 4850 customers. If there were 86 service errors in Division A that year, what was service-error rate, in number of service errors per 100 customers, for Division B of Company X in 1995?

(1) In 1995 the overall service-error rate for Division A and B combined was 1,5 errors per 100 customers. (2) In 1995 Division B had 9,350 customers, none of whom were customers of Division A

In 1995 Division A of the company had 4850 customers, If there were 86 servise errors in Division A that year,what was servise error rate, in number of servise errors per 100 customers in Division B of the company in 1995?

Question \(\frac{x}{B}100=?\) Where x is the servise errors in Division B and B is # of customers of division B.

(1) In 1995 the overall service error rate for Division A and B combined was 1,5 errors per 100 customers.

\(\frac{86+x}{4850+B}=\frac{1.5}{100}\), two variables one equation - can not solve for variables. Also can not get the ratio needed. Not sufficient.

(2) IN 1995 division B had 9350 customers, non of whom were customers for division A

B=9350, clearly insufficient.

(1)+(2) We know the value of B, hence we can calculate x, from (1) and the fraction \(\frac{x}{B}\). Sufficient.

[b] (1) In 1995 the overall service error rate for Division A and B combined was 1,5 errors per 100 customers.

\(\frac{86+x}{4850+B}=\frac{1.5}{100}\), two variables one equation - can not solve for variables. Also can not get the ratio needed. Not sufficient.

In a ratio question, two variables and one equation, can be solved. The issue here is that you cannot simply add the customers of division a and b if you don't know how many overlap

[b] (1) In 1995 the overall service error rate for Division A and B combined was 1,5 errors per 100 customers.

\(\frac{86+x}{4850+B}=\frac{1.5}{100}\), two variables one equation - can not solve for variables. Also can not get the ratio needed. Not sufficient.

In a ratio question, two variables and one equation, can be solved. The issue here is that you cannot simply add the customers of division a and b if you don't know how many overlap

Two variables and one equation can be solved for ratio of the variables only when there is no constant term getting added or subtracted. An equation like \(x + 4850B = 1.5x\) can be solved for ratio of x and B. But an equation like \(\frac{86+x}{4850+B}=\frac{1.5}{100}\) cannot be. The issue here is that you do not have the number of customers of division B. Since the average is weighted, you need to have the number of customers of B to get the error rate of division B. (and in case there is an overlap, then you also need the number of services which were provided together by division A and B and also the overlap in the errors)
_________________

In 1995 Division A of company had 4850 customers. If there [#permalink]

Show Tags

29 Nov 2017, 06:39

Bunuel wrote:

In 1995 Division A of the company had 4850 customers, If there were 86 servise errors in Division A that year,what was servise error rate, in number of servise errors per 100 customers in Division B of the company in 1995?

Question \(\frac{x}{B}100=?\) Where x is the servise errors in Division B and B is # of customers of division B.

(1) In 1995 the overall service error rate for Division A and B combined was 1,5 errors per 100 customers.

\(\frac{86+x}{4850+B}=\frac{1.5}{100}\), two variables one equation - can not solve for variables. Also can not get the ratio needed. Not sufficient.

(2) IN 1995 division B had 9350 customers, non of whom were customers for division A

B=9350, clearly insufficient.

(1)+(2) We know the value of B, hence we can calculate x, from (1) and the fraction \(\frac{x}{B}\). Sufficient.

Answer: C.

Hi Bunuel The overall service error rate for Division A and B combined was 1,5 errors per 100 customers. Can we just plus the (error rate A/customer A) + (error rate B/customer B)? Could you please explain?