Question 671805
Wanda paddles six miles downstream in 1 hour and her friend minnie rowing 1 mph faster goes upstream 6 miles in 2 hours. Find the speed of the current and the girls speeds/rate
I can solve it with whole numbers, but now my teacher tells me the answer should be a number rounded to the hundredths.
I tried 
b-c=3mph
b+c=6mph
2b=9mph
b=4.5mph
so 4.5mph+c=6mph
    c=1.33mph
but plugging that into b+c=6mph comes out to 4.5+1.33=5.83
Maybe that is close enough?
I also tried this formula from the text
Total time=distance upstream(d1)/      + (d2)distance downstream/
           speed of boat upstreamm      speed of boat downstream

or t=  d1/r-c  +  d2/r+c  where r=rate and c=current
but that was not working either.
Any advice on this would be tremendous.
Thanks


Let Wanda’s speed be S, and current’s speed, C
Since Wanda paddled 6 miles downstream in 1 hour, then total speed = 6 mph ({{{6/1}}}). Adding the current's speed to hers, we can say that: S + C = 6 ------ eq (i)


Since Minnie paddled 6 miles upstream in 2 hours, then total speed = 3 mph ({{{6/2}}}). Subtracting the current's speed from hers, we can say that: S - C = 2 ---- eq (ii)


S + C = 6 ----- eq (i)
S - C = 2 ----- eq (ii)
2S = 8 ---- Adding eqs (ii) & (i)
S, or Wanda’s speed = {{{8/2}}}, or {{{highlight_green(4)}}} mph


Minnie’s speed = S + 1, or 4 + 1, or {{{highlight_green(5)}}} mph


4 + C = 6 ------ Substituting 4 for S in eq (i)
C, or current’s speed = 6 – 4, or {{{highlight_green(2)}}} mph


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