BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

If each of the stamps Carla bought cost 20, 25, or 30 cents and she bought

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 1223
Joined: Sat Feb 15, 2020 2:23 pm
Followed by:1 members

If each of the stamps Carla bought cost 20, 25, or 30 cents and she bought

by BTGModeratorVI » Fri May 29, 2020 6:25 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

If each of the stamps Carla bought cost 20, 25, or 30 cents and she bought at least one of each denomination, what is the number of 25-cent stamps that she bought?

(1) She spent a total of $1.45 for stamps.
(2) She bought exactly 6 stamps.

Answer: E
Source: GMAT prep
Top
Source: — Data Sufficiency |
Legendary Member
Posts: 2214
Joined: Fri Mar 02, 2018 2:22 pm
Followed by:5 members

Re: If each of the stamps Carla bought cost 20, 25, or 30 cents and she bought

by deloitte247 » Sun May 31, 2020 4:52 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

Each stamp cost 20, 25 or 30 cents
Total money spent on stamps = 20x + 25y + 30z

Target question => What is the number of 25 cent stamps? i.e find y
Given that she bought at least one of each denomination
Total money is at least 20 + 25 + 30 = 75 cents

Statement 1 => She spent a total of $1.45 for stamps i.e 145 cents
Possible variation in money spent are:
- (20*2) + (25*3 ) + (30*1) = 145 and y = 3
- (20*3) + (25*1) + (30*2) = 145 and y = 1
These 2 possible scenario yield two different value of y. Hence, statement 1 is NOT SUFFICIENT

Statement 2 => She bought exactly 6 stamps
This statement does not give any information about the quality of each stamp because lots of possible variations and ways of arranging 3 different stamps into 6 places i.e 2,2,2; 2,1,3; 1,2,3; so the exact value of y cannot be determined. Statement 2 is NOT SUFFICIENT

Combining both statements together =>
According to the information available in the two statements, the possible scenarios are (20*2) + (25*3) + (30*1) = 145 and (20*3) + (25*1) + (30*2) = 145 and y = 1
The possible scenarios yield different value of y. Hence, both statements together ARE NOT SUFFICIENT

Answer = E
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

Re: If each of the stamps Carla bought cost 20, 25, or 30 cents and she bought

by Brent@GMATPrepNow » Mon Jun 01, 2020 8:48 am

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

BTGModeratorVI wrote: ↑
Fri May 29, 2020 6:25 am
 If each of the stamps Carla bought cost 20, 25, or 30 cents and she bought at least one of each denomination, what is the number of 25-cent stamps that she bought?

(1) She spent a total of $1.45 for stamps.
(2) She bought exactly 6 stamps.

Answer: E
Source: GMAT prep
Target question: What is the number of 25-cent stamps that she bought?

Tricky question!!
We can quickly see that statements 1 and 2 alone are not sufficient.
The hard part comes when we COMBINE the statements.

Statements 1 and 2 combined
After examining some possible scenarios, we get these two conflicting cases:
Case a: Carla bought 2 20-cent stamps, 3 25-cent stamps, and 1 30-cent stamp (6 stamps for a total of 145 cents). In this case, the answer to the target question is Carla bought 3 25-cent stamps
Case b: Carla bought 3 20-cent stamps, 1 25-cent stamp, and 2 30-cent stamps (6 stamps for a total of 145 cents). In this case, the answer to the target question is Carla bought 1 25-cent stamp
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1