Question

A girl can row a boat in down stream 40km in 4hr and upstream 8km in 4hr. Find the speed of boat in still water and in current

Answer 1

let the speed of water be x and speed of current be y

A.T.Q speed for downstream x+y

speed for upstream x-y

when going downstream

speed*time =distance

(x+y)*4=40

x+y= 10----(1)

when going upstream

(x-y)*4= 8

x-y=2-----(2)

by elimination method:

x+y=10

x-y= 8

by adding

2x=18

x=9

and y = x+y=10

9+y=10

y=1

hope it helps u