Instructions:
The table describes the number of passengers entering and leaving at stations A, B, C ... Bus arrives without passengers at the first station. All passengers get off on the last station. We do keep rules of decency - first get off and then get in.
Example
A
B
C
D
E
got off
0 0
0 3
0 1
1 1
7 8
got on
3 7
0 0
in bus
1 3
3 3
altogether
15
Solution
A
B
C
D
E
got off
0 0
0 3
0 1
1 1
7 8
got on
1 3
2 3
2 0
3 7
0 0
in bus
1 3
3 3
5 2
7 8
altogether
4
6
7
15