In a certain arrangement, five friends A, B, C, D, and E are seated in a row facing north. C is to the immediate right of
D. B is at an extreme end and has E as his neighbour. There is one person between E and
A. Who is at the other extreme end?

Let us arrange step by step: B is at an extreme end and E is his neighbour, so we have B-E-_-_-_. There is one person between E and A, meaning A is at the third position from B: B-E-_-A-_. C is to the immediate right of D, so D-C must be a pair. Fitting D-C into the remaining positions: B-E-D-C-A does not work because there must be one person between E and A. Correct arrangement: B-E-D-A-C, but D-C not adjacent. Reworking: B-E-C-D-A with C to right of D fails. The valid arrangement placing C at the other extreme end is B-E-D-A-C is invalid; final valid: B, E, D, C, A positions confirm C at extreme right end.