The speed of the man in still water is 40 kmph. If he can row upstream at 20 kmph, find the downstream.  Choose the correct choice from the following answers.
A) 40	B) 50	C) 55	D) 60	E) 65
M = (60S + US)/2   60S=2M-US   = 2*40-20= 
<gadget id="calculator">2*40-20</gadget>
<output>60</output>
60   Answer:60
<result>D</result>
The speed of the man in still water is 40 kmph. If he can row upstream at 20 kmph, find the downstream.