This question is not difficult, but the organization should be clear, and many people may not even understand this.

Starting point: on board 10 people.

Station 1: there are 10 people on the bus (meaning that there are 1 people getting off at every station just behind, and there are 10 stations left, so there are 10 people on the bus), and there are ***20 people on the bus.

2 stops: 9 people get on (there are 9 stops left, so 9 people), 1 people get off (10 people get off at 1 station), and 28 people get on.

3 stops: 8 people get on and 2 people get off (key! Station 1 and station 2 have 1 people, so there are 2 people), ***34 people.

4 stops: 7 people get on, 3 people get off ***38 people.

5 stops: 6 people get on and 4 people get off ***40 people.

6 stops: 5 people get on, 5 people get off or 40 people. (2 times full)

7 stops: 4 people get on, 6 people get off ***38 people. (begin to decrease)

8 stops: 3 people get on, 7 people get off and 34 people.

9 stops: 2 people get on, 8 people get off and 28 people.

10 station: 1 people get on, 9 people get off and 20 people get off.

1 1 station: all 20 people get off. The driver should also get off and have a rest. )