Total number of seats = (8 rows) x (15 seats per row) = 120 seats.
Number of occupied seats:
(5 rows) x (15 seats per row) = 75 seats
people sitting alone in next row = 3 seats
Total occupied = (75 + 3) = 78 seats
Empty seats = (total seats) minus (occupied seats) = 120 - 78 = 42 empties
