The total time taken by the boat to cover 72 km upstream and 180 km downstream is 16 hours. The total time taken by the same boat to cover 108 km upstream and 126 downstream is 16 hours. If the sum of the upstream speed and downstream speed of the boat is 30 km, then find the speed of the stream.
1
2 kmph
2
5 kmph
3
3 kmph
4
4 kmph
5
1.5 kmph