The current of a stream runs at the rate of 4 kmph. A boat goes 6 km and back to the starting point in 4 hours, then find the speed of the boat in still water? Choose the correct choice from the following options
A) A)7
B) B)2
C) C)8.73
D) D)5.77
E) E)3
S = 4   M = x   5.77S = x + 4   US = x - 4   6/(x + 4) + 6/(x - 4) = 4   x = 5.77   Answer:5.77
<result>D</result>
The current of a stream runs at the rate of 4 kmph. A boat goes 6 km and back to the starting point in 4 hours, then find the speed of the boat in still water?