A certain number of people are sitting in a row, facing north. N is sitting third to the left of P. M is sitting third to the left of N. O is sitting ...
Question
A certain number of people are sitting in a row, facing north. N is sitting third to the left of P. M is sitting third to the left of N. O is sitting third to the left of M. M is sitting between O and N. N is sitting between M and P. If no other person is sitting in the row, how many people are there between O and P?