<PRE><B>Question 912719</B>
Gertrude rows her boat 24 miles downstream in 4 hours. In order to make the return trip upstream in the same amount of time, the rate of the boat in still water was doubled. Find the rate of the current and the rate of the Gertrude was rowing downstream. 


Gertrude rows her boat 24 miles downstream in 4 hours.
let boat speed in still water be x
let rate of current be y

t=d/r

{{{24/(x+y) =4}}}

24=4(x+y)
x+y = 6.................................(1)


 In order to make the return trip upstream in the same amount of time, the rate of the boat in still water was doubled. = 2x


t upstream = {{{24/(2x-y)=4}}}


2x-y = 6................................(2)

add (1) &amp; (2) 

we get 3x=12
x=4.......speed of boat in still water
speed of current = 2mph

speed of boat upstream = 2*x= 2*4= 8 mph






 Find the rate of the current and the rate of the Gertrude was rowing downstream. 
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