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
Target Test Prep is 20% off right now!
Use code FLASH20
Available with Beat the GMAT members only code
MORE DETAILS
Of all houses on Kermit Lane, 20 have front porches, 20 have
This topic has expert replies
-
BTGmoderatorLU
- Moderator
- Posts: 2209
- Joined: Sun Oct 15, 2017 1:50 pm
- Followed by:6 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
GMAT/MBA Expert
-
Ian Stewart
- GMAT Instructor
- Posts: 2621
- Joined: Mon Jun 02, 2008 3:17 am
- Location: Montreal
- Thanked: 1090 times
- Followed by:355 members
- GMAT Score:780
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
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.
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
ianstewartgmat.com
-
deloitte247
- Legendary Member
- Posts: 2214
- Joined: Fri Mar 02, 2018 2:22 pm
- Followed by:5 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
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,
$$Answer\ is\ Option\ A$$
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,
$$Answer\ is\ Option\ A$$
