Question

A row of seats in a stadium has 100 seats. If 12 people sit in a row so that there are 2 empty seats between any person and the next person, how many empty seats in the rpw are not between the two end people?

Answer 1

If there are four seats per row, one person sits at each end, and two spaces will be between them. The same goes for 7 seats, namely the first, fourth, and seventh will be occupied. Continuing this way, we know that seats will be occupied on the
1st, 7th, 10th, 13th, .... (3n+1)th.
So which is the occupied seat below or equal to the 100th seat?