Franny can type 80 words per minute and Matt can type 60...

Expert replies

AAPL: Moderator; Posts: 2710; Joined: Sun Oct 29, 2017 2:08 pmFollowed by: 2 members

by AAPL » Mon Mar 26, 2018 4:54 am

Franny can type 80 words per minute and Matt can type 60 words per minute. If the two together must type up a 14,000-word paper and each person can type for at most 2 hours, what is the least amount of time, in hours, that Matt must type?

A. 2
B. 5/6
C. 11/12
D. 11/9
E. 35/9

The OA is D.

Franny's efficiency = 80 words per minute = 4800 words/h

Matt's efficiency = 60 words per minute = 3600 words/h

Franny completes 9600 words in 2 hours and is left with 4400 words for Matt to complete.

Matt will complete that in 4400/3600 = 11/9 hours.

Is there another strategic approach to solve this PS question? Can any experts help, please? Thanks.

Like this post

Source: Beat The GMAT — Problem Solving | Mon Mar 26, 2018 4:54 am

GMAT/MBA Expert

ErikaPrepScholar: Legendary Member; Posts: 503; Joined: Thu Jul 20, 2017 9:03 amFollowed by: 15 members; Thanked: 86 times; GMAT Score:770

by ErikaPrepScholar » Mon Mar 26, 2018 10:49 am

We could also approach using dimensional analysis.

Franny:
$$2\ hours\ \left(\frac{60\ \min}{1\ hour}\right)\left(\frac{80\ words}{1\ \min}\right)=9600\ words$$

Matt:
$$14000\ words\ -\ 9600\ words\ =\ 4400\ words$$
$$4400\ words\ \left(\frac{1\ \min}{60\ words}\right)\left(\frac{1\ hour}{60\ \min}\right)=\frac{11}{9}hours$$

This is the same process you used, just slightly reordered and slightly more efficient.

We can also eliminate E right off the bat because 35/9 is greater than 2, which violates the rule that each person can type for at most two hours.

Erika John - Content Manager/Lead Instructor
https://gmat.prepscholar.com/gmat/s/

Get tutoring from me or another PrepScholar GMAT expert: https://gmat.prepscholar.com/gmat/s/tutoring/

Learn about our exclusive savings for BTG members (up to 25% off) and our 5 day free trial

Check out our PrepScholar GMAT YouTube channel, and read our expert guides on the PrepScholar GMAT blog

Like this post

GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8212; Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members; Location: Los Angeles, CA; Thanked: 43 times

by Scott@TargetTestPrep » Wed Mar 28, 2018 10:16 am

AAPL wrote:Franny can type 80 words per minute and Matt can type 60 words per minute. If the two together must type up a 14,000-word paper and each person can type for at most 2 hours, what is the least amount of time, in hours, that Matt must type?

A. 2
B. 5/6
C. 11/12
D. 11/9
E. 35/9

We are given that Franny can type 80 words per minute or 80 x 60 = 4800 words per hour. To minimize the amount of time Matt must type, we must maximize the amount of type Franny types, which is 2 hours. If she types for 2 hours (the maximum she can type), then she will have typed 4800 x 2 = 9600 words. Thus, there are 14,000 - 9600 = 4,400 words remaining for Matt to type.

Since Matt can type at a rate of 60 words per minute, or 60 x 60 = 3600 words per hour, the time he will have to spend typing is:

4,400/3,600 = 44/36 = 11/9 hours

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

563 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (563 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review