Any mathematicians out there??

Does anybody want to have a crack at an algebraic puzzle, I have not got very far i.e. nowhere at all.
'A small swimming pool can be filled with two pipes in 3 hours. If the larger pipe alone takes 8 hours less than the smaller pipe to fill the pool, find the time in which it will be filled by each pipe singly.'
Thanks,
Max
'A small swimming pool can be filled with two pipes in 3 hours. If the larger pipe alone takes 8 hours less than the smaller pipe to fill the pool, find the time in which it will be filled by each pipe singly.'
Thanks,
Max
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Large pipe must be more than 3 hours, so small pipe must be more than 11.
And I can't get further than that.
I feel it, when I sorrow most;
'Tis better to have loved and lost;
Than never to have loved at all."
Alfred Tennyson
Max
http://dottyjumper.posterous.com/
http://twitter.com/#!/MaxGloger
PMed.
I feel it, when I sorrow most;
'Tis better to have loved and lost;
Than never to have loved at all."
Alfred Tennyson
Make the pool 300 units in size. Make the rates of the two pipes X and Y units per hour. (Y is the faster)
Therefore 300/3=X+Y. So X=100-Y
And 300/X - 8 = 300/Y
Multiply by X and Y: 300Y -8XY= 300X
Substitute X: 300Y -800Y +8Y^2 = 30,000 -300Y
Simplify: Y^2 -25Y -3,750 = 0
Solve : Y= 75 so X=25
Therefore times are 300/75 and 300/25. 8 hours and 4 hours.
:shock: :shock: :? :? :oops: :oops:
I is fick :oops:
FCN3
http://img87.yfrog.com/img87/336/mycubeb.jpg
http://lonelymiddlesomethingguy.blogspot.com/
Pool Full = 1 (arbitrarily)
large pipe time alone = x
small pipe time alone = y,
y = x+8
3 hours is the total time so you divide it by the individual pipes to get their contribution.
(3/x+8 ) + (3/x) = 1
times by x(x+8 ) gives
3x + 3(x+8 )l = x(x+8 )
3x + 3x+24= x^2 + 8x
(-6x, - 24) equals
0 = x^2 + 8x - 6x - 24
0 = x^2 + 2x - 24
0 = (x-4)(x+6)
only positive answer is that x (large pipe) = 4
therefore y (small pipe) = x+8 = 12.
I feel it, when I sorrow most;
'Tis better to have loved and lost;
Than never to have loved at all."
Alfred Tennyson
The maths is essentially the same though.
http://dottyjumper.posterous.com/
http://twitter.com/#!/MaxGloger
Winter
Racey
Special Favourite
If in doubt, blame Wiggle.
north west of england.
Pool filled in 3 hours (originally), than a leak appeared!!
If full, the pool completely empties in 5 hours through the annoying leak.
How long does the pool take to fill, bearing in mind the annoying leak?
I feel it, when I sorrow most;
'Tis better to have loved and lost;
Than never to have loved at all."
Alfred Tennyson
Edit - no, 7.5 hours ...
It's not technically homework, just a small pack to stop me forgetting everything over the holidays!
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http://twitter.com/#!/MaxGloger
By the way... can someone explain in layman's language how binary works? In 1st year at Secondary I was a lazy git so got kicked out of the top class into the next one down - they had already done binary, we hadn't, so I missed it. There was a question on my O-level paper using binary and I couldn't even attempt it. Ta.
We all show thickness in different ways. I didn't realise it was a bank holiday until they mentioned it on the radio at 8.30 on Monday morning. Now that's thick.
This looks interesting...
The above post may contain traces of sarcasm or/and bullsh*t.
north west of england.
http://dottyjumper.posterous.com/
http://twitter.com/#!/MaxGloger
http://dottyjumper.posterous.com/
http://twitter.com/#!/MaxGloger
http://dottyjumper.posterous.com/
http://twitter.com/#!/MaxGloger
Good to know that 31 years after leaving school, and having to learn sufficient algebra to pass various science exams, that I still don't understand it, I still can't do it and, what's more, during my entire working life I've never needed to.
Bob
2nd one is right.
I feel it, when I sorrow most;
'Tis better to have loved and lost;
Than never to have loved at all."
Alfred Tennyson