Question

A boat goes 30 km upstream and 44 km gownatream in 10 hours.In 13 hours it go 40 km upstairs and 55 km downstteam.Determine the speed of the the stream and that of the boat in still water.

Answer 1

hope this help....... ..

Answer 2

Boat and stream; speed=distance/time
time=d/speed
Distance in upstream=30km
Distance in downstream=44km
 upstream and downstream in 10hrs
speed of upstream=(u-v)km/h
speed of downstream=(u+v)km/h
t1=30/u-v ; t2=44/u+v
t1+t2=10 hrs
30/u-v+44/u+v=10
Similarly 40/u-v + 55/u+v=13
Take 1/u-v=x and 1/u+v =y
30x+44y=10........1
40x+55y=13.........2
solving 1 and 2
we get y=1/11
Substitute y=1/11 in equation 1
30x+44(1/4)=10
30x+4=10
30x=6
x=6/30=1/5
If x=1/5 then u-v=5.....3
y=1/11 then u+v=11....4
solving 3 and 4
2u=16
u=8kmm/hr
v=3km/hr