Bunuel
Each of three students is given fifteen tokens to spend at a fair with various tents to visit. Some tents cost 3 tokens to enter, and some, 4 tokens. How many tents did Amelia visit?
(1) Amelia bought one token from another classmate, and spent all the tokens in her possession.
(2) Not all of the tents Amelia visited were the same token-price.
MAGOOSH OFFICIAL SOLUTION:This is a tricky problem.
Statement #1: Amelia had 16 tokens in total, and spent them all. How could she do this with a combination of 3-token tents and 4-token tents? Well, there are two possibilities.
Case I: Amelia visited four 4-token tents, four tents in total.
Case II: Amelia visited one 4-token tent and four 3-token tents, five tents in total
Since this statement leaves us with the ambiguity with four vs. five tents, we cannot give a definitive answer to the prompt question. This statement, alone and by itself, is insufficient.
Statement #2: This statement, by itself, tells us very little. How many tokens did Amelia have? Did she spend all the tokens in her possession? We have no way of knowing, so no way to answer the prompt question. This statement, alone and by itself, is insufficient.
When we combine the statements, the second one becomes more significant. Of the two cases given in statement #1, the first involves four trips to tents of the same token-price, so case #1 is not consistent with statement #2. That leaves only case #2, which means that Amelia had to have visited exactly five tents. Combining the statements allows us to give a definitive answer to the prompt question. Combined, the statements are sufficient.
Answer = (C)