A boat can cover a distance of 7.2 km downstream and 3.2 km upstream in 2 hours. It can also cover 1.5 km downstream and 0.6 km upstream in 24 minutes. What is the speed of the boat when going downstream (in km/h)?
1
5
2
\(7\frac{1}{2}\)
3
\(4\frac{1}{2}\)
4
6