BTGModeratorVI wrote: ↑Thu Nov 26, 2020 1:14 pm
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
