Five subjects S1, S2, S3, S4 and S5 (not necessarily in the same order) are taught from Monday to Friday. One subject will be taught one day. Only S5 is taught before S1. S2 is taught before S4. S5 will not be taught on Wednesday. Which of the following pairs of subjects is taught after S3?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → S2, S4
Each day has one subject, so the five subjects fill Monday to Friday in some order. The clues are placed one by one:
Only S5 is taught before S1, so only one day comes before S1: S1 is on Tuesday and S5 on Monday (which also keeps S5 off Wednesday).
S2, S3 and S4 take Wednesday, Thursday and Friday, with S2 before S4.
The question asks for a pair taught after S3. Two subjects come after S3 only if S3 is on Wednesday; then S2 is on Thursday and S4 on Friday.
S1 and S5 are taught before S3, so every other pair includes a subject that does not come after S3; the pair after S3 is S2, S4.