Challenging Qn for Brain

[Hobbiez]

Just a brain teaser Qn for you:

 

2 pipes takes 5 minutes to fill up a tank, and the smaller pipe alone takes 6 minutes more than the bigger pipe to fill the tank. How long would it takes for the bigger pipe to fill the tank alone?

 

I will provide the answer shortly.

Edited September 21, 2007 by Hobbiez

[Rastaman01]

0 min cause the tank is filled already

[Epr0mlse]

5.5 mins?

[Freestylers09]

2 mins?

[Flight_skoda]

Hmmm... my guess is 2 mins as well.

[Baka]

I too lazy to work out the exact mathematical calculation, but my 6th sense tells me it's close to 7min ??

((5min x 2)-(6min/2))

[Mivec9]

5( x/(y+6) + x/(y)) = x

5y + 5y + 30 = y^2 + 6y

y^2 - 4y - 30 = 0

y = (4 + 11.66)/ 2 = 7.83

[Flight_skoda]

Wha ... so technical, see until I

[Baka]

Can anyone tells me this is a question for which level? I need to be mentally prepared for the day that my son's maths will outshine mine...

[Mivec9]

guess is interest....it looks difficult but if u understand it...it shd be ok

[Moodyzzz]

the bigger pipe will take 6mins lesser than the smaller pipe to fill the tank.

[Mivec9]

looks like elementary maths to me

[Baka]

elementary math means E maths in A level or PSLE maths?

 

I think someone who dunno this would still be able to get through degree in accountancy in my times..

[Mivec9]

E maths...but i'm not sure is it A level standard. A-Maths will be different category.

[Baka]

I remembered my maths knowledge peaked at A levels when I have to know calculus and some other crazy maths stuff, which was later rather useless in Uni days and even more useless now in working life.

 

Now my higher maths rusty liao due to little usage. Just use a financial calculator or Excel and things get computed immediately.

 

But I know these maths problem will haunt me again when my son eventually have to go through the horrible maths questions.

[Kaka23]

6min?

Edited September 21, 2007 by Kaka23

[Slowmo]

3 mins

 

 

(I'm feeling lucky)

[Icekitten]

8 minutes.