Question

A boat takes 1 hour longer to go 36 km up a river than
to return. If the river flows at 3 km/hr, find the rate at
which the boat travels in still water.

please answer fast in step by step explanation ​

Answer 1

Answer:

15 km/hr

Step-by-step explanation:

Let x be speed of boat in still water

To go upstream = x-3

To go downstream = x+3

Upstream - Downstream = x-3 - x+3

#by cancelling the equation we get = 1

now, A.T.Q

36/x-3 - 36/x+3 = 1

now reciprocal x digits:

36 x (x+3) - 36 x (x-3) = 1

36x + 108 - 36x + 108 = (x+3) (x-3) = x2 - 9

now,

x2-9 = 116

x2 = 116 + 9 = 225

x2 = 225

(((x = 15 km/hr )))

hope it helps you