UCAT Question Analysis - Decision Making Question 72
The following are 4 suspects from a recent robbery. One or more of them are guilty.
- If Fred is guilty, all are guilty.
- If Theo is guilty, he has two accomplices.
- If Eddie is innocent, Theo is guilty.
- If Victor is guilty, there will be only two guilty suspects.
Which of the following MUST be true?
A. Eddie is guilty.
B. Eddie ALONE is guilty,
C. Victor is guilty.
D. Eddie OR Victor is guilty but NOT both.
Answer & Explanation
Answer: A
Explanation:
1. If Fred is guilty, all are guilty, meaning Victor is guilty too. But if Victor is guilty then there are 2
guilty suspects. Impossible for all to be guilty in this case, so Fred must be innocent
2. If Theo is guilty, he has 2 accomplices, meaning there will be 3 people guilty. Known that Fred is
innocent, meaning that Victor is guilty as he is the remaining 3 people. BUT if
Victor is guilty, there will be only 2 suspects. Contradictory. Theo is not guilty.
3. The remaining suspects: Eddie and Victor. If Eddie is innocent, Theo is not. Since Theo is innocent, Eddie
cannot be innocent. Hence, Eddie is guilty.
4. Since Victor might be guilty, there are no options concluding the 2 guilty suspects are Victor and Eddie.
Hence options B, C and D cannot be concluded as definitely true.
Drafted by Quincy (UCAT Prep)