A, B, C, D, E, and F live on six different floors of the same building, numbered 1 to 6 from bottom to top. C lives on a prime-numbered floor. The product of the floor numbers of C and B is 8. E lives immediately above F. The sum of the floor numbers of B and D is 7. How many people live between A and D?

Seven people, M, N, O, P, X, Y, and Z are sitting in a row, facing north. No one sits to the left of X. Only four people sit between X and O. Only three people sit to the right of M. Z sits to the immediate left of N. P is not an immediate neighbor of M. Who sits at the rightmost end of the line?

Five students are sitting in a row facing North. Akbar is to the left of the person sitting in the middle, but to the right of Sekar. Prakash is to the right of Deva, and Ram is to the right of Prakash. Ram is second from the person sitting in the middle. Who is the person sitting in the middle?