Of all houses on Kermit Lane, 20 have front porches, 20 have

Expert replies

Previous Topic Next Topic

BTGmoderatorLU: Moderator; Posts: 2607; Joined: Sun Oct 15, 2017 1:50 pmFollowed by: 6 members

by BTGmoderatorLU » Tue May 28, 2019 5:51 pm

Timer

00:00

Answers

Stats

Difficulty—

Source: Manhattan Prep

Of all houses on Kermit Lane, 20 have front porches, 20 have front yards, and 40 have back yards. How many houses are on Kermit Lane?

1) No house on Kermit Lane is without a back yard.
2) Each house on Kermit Lane that has a front porch does not have a front yard.

The OA is A

Like this post

Source: Beat The GMAT — Data Sufficiency | Tue May 28, 2019 5:51 pm

GMAT/MBA Expert

Ian Stewart: GMAT Instructor; Posts: 2623; Joined: Mon Jun 02, 2008 3:17 amFollowed by: 355 members; Location: Montreal; Thanked: 1090 times; GMAT Score:780

by Ian Stewart » Sat Jun 01, 2019 6:00 am

If every house has a back yard, and, as Statement 1 tells us, 40 houses have a back yard, there are 40 houses in total, so Statement 1 is sufficient.

From Statement 2, if a house has a front porch, it does not have a front yard. So if a house has a front yard, it cannot have a front porch. So we have 20 houses with only the porch, and 20 with only the yard, for a minimum of 40 houses in total. But some houses might have neither a porch nor a yard, so we don't know how many houses we have in total, and the answer is A.

For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com

Like this post

deloitte247: Legendary Member; Posts: 2214; Joined: Fri Mar 02, 2018 2:22 pmFollowed by: 5 members

by deloitte247 » Fri Jun 07, 2019 12:50 pm

How many houses are on kermit Lane?
Statement 1
No house on kermit lane is without back yard
This means that all house on kermit lane have a backyard since number of houses with backyard = 40
Therefore, 40 houses are on kermit lane.
Statement 1 is SUFFICIENT.

Statement 2
Each house on kermit lane that have a front porch does not have a front yard
This means that houses with front porch and front yard are disjoint set with no intersection, but there is no information relating to the number f houses with backyards, so it is difficult to arrive at a definite conclusion for the number of houses on kermit lane.
Hence statement 2 is INSUFFICIENT.
Since statement 1 alone is SUFFICIENT,

$$Answer\ is\ Option\ A$$

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