A man can row 9 1/3 km/hr in still water and he finds that is thrice as much time to row u p than as to row down the same distance in river. The speed of the current is:________?

A. 3 1/3 km/hr
B. 3 1/9 km/hr
C. 1 ¼ km/hr
D. 4 2/3 km/hr
Explanation:
Let Speed upstream = x km/hr
Speed downstream = 3x km/hr
Speed in still water = ½ (x+3x) km/hr = 2x km/hr
Speed of current = ½ (3x-x) km/hr = x km/hr
2x = 28/3 or x = 14/3 = 4 2/3 km/hr