Question

A boat travels upstream from b to a and downstream from a to b in 3 hours. if the speed of the boat in still water is 9 km/hour and the speed of the current is 3 km/hour, the distance between a and b is

Answer 1

Speed of the boat in still water = 9 km/hr
Speed of the current = 3 km/h,

Speed downstream = 9+3 = 12 km/hr
Speed upstream = 9-3 = 6 km/hr

Let the distance between A and B be xx. Then
x6+x12=3x+2x=363x=36x=12x6+x12=3x+2x=363x=36x=12  
ANSWER=12