Maths Problem (simple)

My guess (and I was terrible at these problems in High School) is 1 mile, because, with the current, the boat is going 2 MPH and it's passing the bridge, so it's got to go an equal distance beyond the bridge and then back in order to pass it without any other turns (e. g. it goes right back to the beginning).

1 3/5 miles up stream.

Not bad eh at 11.45 pm without pencil and paper and after 5 bottles Becks?

er might be being a little premature here, but am too lazy to go and fetch pencil and paper, besides tired going to bed 'nighty night

Not bad Steve if really done in the head ! You might have to explain it .

Well it was done in my head, but it nearly did my head in as well!

I'm not going to type out the solution. But the method is simple enough. There are two equations linking the two times t1 and t2 which are the times the boat takes to reach and then return from the point at which it turns round. The first equation is simple t1+t2=1

The other links t1 and t2 by the equal distances to and from the turn round point.

What the heck nearly done it now

Going up stream distance travelled (distance=speed*time) = 2(t1)
going down stream distance = 8(t2)

But the distance is the same so 2(t1)=8(t2)

From first equation, t1=1-t2
substituting in above 2(1- (t2))=8(t2)
2-2(t2)=8(t2)
therefore t2=1/5 hour
boat travels back from turn point for 1/5 hour at 8mph
therefore distance to turn point must be (1/5)*8= 1 3/5 mi
QED

gwapa KOh!!
why am i pretty??my GOD!!i bAreLy dont kNOw..huhuhuhu...