Six girls M, N, O, P, Q and R are sitting on a bench facing towards the east. M is sitting between P and Q. Only two girls are sitting to the right of Q. R is sitting to the immediate left of P. Who is sitting at the extreme left end?

Let's denote the six linear positions on the bench from Left (1) to Right (6). Facing East means standard linear tracking applies directly:
"Only two girls are sitting to the right of Q". This uniquely fixes Q at position 4 (slots 5 and 6 are to her right). So, Q = 4.

"M is sitting between P and Q". Since Q is at 4, M must be adjacent to Q.

If M is at 5, P would be at 6 (but then M wouldn't be between P and Q from the standard left-to-right flow).

Therefore, M must be at position 3, and P must be at position 2. So, M = 3 and P = 2.

"R is sitting to the immediate left of P". Since P is at position 2, its immediate left is position 1. So, R = 1.

The remaining slots are 5 and 6, which will be occupied by the remaining girls N and O.

The arrangement from left to right starts with:
Position 1: R

Therefore, R is sitting at the extreme left end.