Question

a Boat goes 30 km upstream and 44 kilometre downstream in 10 hours in 13 hours it can go 40 kilometre upstream and 55 km downstream determine the speed of the stream and that of the boat in still water​

Answer 1

Answer:

here you go,

Step-by-step explanation:

Let the speed of boat in still water be X km/h and speed be Y km/h

speed upstream = (x-y)km/h

speed downstream = (x+y)km/h

let 1/x-y=a and 1/x+y=b

30/x-y + 44/x-y=10=30a+44b=10

=120a+176b=40

40/x-y + 55/x+y=13=40a+55b=13

=120a+165b=39

on subtracting,we get,

b=1/11

30a+4=10=30a=b=a=1/5

x-y=5 and x+y=11

on solving , we get

x=8 , y=3

speed of boat in still water =8/km/h

and , speed of stream=3/km/h