Im too retarded to solve this on my own, care to help? It takes

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>Hurt my brain trying to work it out and have sudden urge to hit myself

>>35532024
wouldn't the speed of the boat be zero since its still water meaning not moving at all?

i feel like this just a trick question.

>>35532024
It doesn't give you enough information to work this out, surely. How long is the stream?

>>35532024
Speed = D/T
-3mph + X = D/3 hours
X = D/3 + 3
3mph + X = D/2 hours
X = D/2 - 3
D/2 - 3 = D/3 + 3
D/2-D/3 = 6
D = 36

Upstream speed: 18 mph
Downstream speed: 12 mph
Still speed: 18-3 or 12 + 3, 15mph

>>35532907
>>35533077
>>35533130
Brainlets

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rate times time equals distance

(rate_boat - 3) * 3 = d
(rate_boat + 3) * 2 = d

(r - 3) * 3 = (r + 3) * 2
3r - 9 = 2r + 6
r = 18 mph

>>35533251
9+6 isn't 18, it's 15

>>35532024
>tfw learned all this a while ago
>don't even know where to begin anymore

Fuck, I shouldn't have taken a year off. Hope I get a good teacher when school starts, otherwise I'm fucked

>>35532024
vb = velocity of boat
vr = 3mph
t1 = 3h
t2 = 2h
d = distance covered in both trips

vb - vr = d/t1
vb + vr = d/t2

set the vb terms equal to each other:
=> d/t2 - vr = d/t1 + vr
=> d(1/t2 - 1/t1) = 2vr
=> d = 2vr/(1/t2 - 1/t1) = 2(3)/(1/2 - 1/3)

=> d = 36 miles
=> vb = 15 mph

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>>35533333
110% checked, quintmaster

>>35533333
>only 1 check
Sad desu

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>>35533523
>>35533574
I didn't even notice, thanks anons

>>35533333
checked and also correct answer

>>35533333
Nice get
Origin41