A man rows from A to B (upstream) and B to A (downstream) in 12 hours. The distance between A and B is 240 km. The time taken by the man to row 6 km downstream is identical to the time taken by him to row 4 km upstream. What is the speed of the stream?
1
\(\rm \frac{35}{3}\ km/h\)
2
\(\rm \frac{25}{3}\ km/h\)
3
\(\rm \frac{46}{3}\ km/h\)
4
\(\rm \frac{50}{3}\ km/h\)