Five subjects S1, S2, S3, S4 and S5 (not necessarily in the same order) are to be taught from Monday to Friday. One subject will be taught on one day. Only S5 is taught before S1. S2 is taught before S4. S2 will not be taught on Wednesday. Which of the following pair of subjects is taught after S3?

From the given statement only S5 will be taught before S1,hence only one possibility is there to put S5 on Monday and S1 on Tuesday and S2 will not be taught on Wednesday but before S4 so only one possibility is there to put S4 on Friday and S2 on Thursday. Hence the remaining place is occupied by S3 on Wednesday.So,the sequence will follow like this;

MONDAY            S5   

TUESDAY           S1

WEDNESDAY      S3      

THURSDAY         S2

FRIDAY               S4

Hence , S2 and S4 is taught after S3,so the correct option is (d)