2007-05-18 05:54:50 · 8 answers · asked by MANZOOR RAHIM T 1 in Science & Mathematics ➔ Mathematics
assuming he rows at the same speed up and down,
18km in 4 hours = 4.5 km/hour with the stream
18km in 12 hours = 1.5 km/hour against the stream
avg speed = 3km/hour
so stream flow rat is 1.5km/hr.
2007-05-18 06:00:02 · answer #1 · answered by ed the ash 3 · 0⤊ 0⤋
Downstream
Let rate of flow of stream = x km/h
boat rate = y km/h
Combined rate = (x + y) km/h
x + y = 4.5
Upstream
x - y = 1.5
x + y = 4.5
x - y = 1.5
2x = 6
x = 3
Rate of flow of stream = 3 km / h
2007-05-18 17:51:45 · answer #2 · answered by Como 7 · 0⤊ 0⤋
Yar incomplete Q mat diya karo.
Kutch log samajdar hain
2007-05-18 13:58:18 · answer #3 · answered by Anonymous · 0⤊ 0⤋
let his speed in still water be 'x' kph and speed of the stream/river be 'y' kph
speed upstream=x-y kph and downstream x+y kph
the equation
18/(x+y)=4
18/(x-y)=12
4x+4y=18
4x-4y=12
adding
8x=30
so x=3.75
substituting 15+4y=18
4y=3
y=0.75
so his speed in still water=3.75 kph and the speed of the river is 0.75 kph
2007-05-18 13:01:24 · answer #4 · answered by raj 7 · 0⤊ 0⤋
Do you really have anything better to do than post these incomplete questions?
2007-05-18 12:56:42 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Finish the question and I'll help you.
2007-05-18 13:02:58 · answer #6 · answered by Emily 2 · 0⤊ 0⤋
pretty dang fast
2007-05-18 12:58:39 · answer #7 · answered by Geronimo X 2 · 0⤊ 0⤋
wow... thats an easy one...!!! the answers kinda secret though...!!! just like your question...!!!
2007-05-18 18:06:34 · answer #8 · answered by ash3_phoenix 2 · 0⤊ 0⤋