Question

It takes a boat going upstream 11 hours to cover the same distance, as it would cover in 9 hours going downstream. What is the speed of the boat if the speed of the current is 2 km/hr?

Answer 1

Answer:

20 km/hr

Explanation:

time taken by the boat going upstream = 11 hours

time taken for downstream movement = 9 hours

speed of the current = 2 km/h

distance traveled by the boat = d

Assume the speed of boat be x

we know,

distance =  speed × time

moving upstream

distance = speed × time

            d  = (x -2) × 11

downstream

             d = (x+2) × 9

now  

       (x+2) × 9 = (x -2) × 11

              2 x = 40

                 x = 20 km/hr

hence, the speed of the boat will be 20 km/hr