LSAT (Law School Admission Test)Analytical ReasoningMedium
A librarian is arranging six new books—F, G, H, I, J, K—on a single shelf from left to right, positions 1 through 6. The arrangement must conform to the following conditions: 1. F must be in an earlier position than G. 2. H must be in position 3. 3. J must be next to K. 4. I cannot be in position 1. 5. G cannot be in position 6. If J is in position 4, which of the following books could be in position 1?
- AK
- BG
- CF
- DI
Show answer & explanationAnswer & explanation
Correct answer: C. F
If J is in position 4, then K must be in position 3 or 5 (rule 3). However, H is in position 3 (rule 2), so K must be in position 5. This leaves F, G, I for positions 1, 2, 6. I cannot be in position 1 (rule 4). G cannot be in position 6 (rule 5). F must be before G (rule 1). The only way to satisfy these is F in 1, I in 2, G in 6 (but G cannot be 6) OR F in 1, G in 2, I in 6. The latter works. Therefore, F can be in position 1.
Why the other options are wrong
- A. If J is in position 4, K must be in position 5 (since H is in 3). So K cannot be in position 1.
- B. If G is in position 1, then F cannot be in an earlier position than G, violating rule 1.
- D. I cannot be in position 1 due to rule 4.
Conditional Possibility Check
Determining which arrangements are possible or which items can occupy a specific position, given an additional constraint and all original rules.
- Involves exploring one or more valid scenarios under a new condition.
- Requires careful application of all rules to the new setup.
- Often uses process of elimination for options that violate rules.
Memory trick: Position + Rules = Possible Book!