1. A bus was three stops away from the bus terminal. At the first bus stop, 5 passengers got on and 3 passengers got off. At the second bus stop, 4 passengers got on and 8 passengers got off. At the third bus stop, 2 passengers got on and twelve passengers got off. When the bus arrived at the terminal, all 75 passengers got off. How many passengers were on the bus just before it arrived at the first bus stop?
​