Friday, January 1, 2010

Stealing Wine

A dishonest servant takes out 3 pints of wine from a barrel and replaces them with the same amount of water. He repeats this theft twice, removing in total 9 pints and replacing them with water. As a result of this swindle, the diluted wine remaining in the barrel lost half of its former strength.

How much wine was in the barrel before the thievery began?

3 Comments:

Anonymous Anonymous said...

A= mass of alcohol
V= volume in barrel
S= concentration of wine i.e. alcohol per volume

Ao=V*So


A1=So*V-So*3
S1=A1/V

A2=S1*V-S1*3
S2=A2/V

A3=S2*V-S2*3
S3=A3/V=0.5*So



A2=So*(V-3)-3/V*So*(V-3)

A3= (So*(V-3)-3/V*So*(V-3))-3/V*[ So*(V-3)-3/V*So*(V-3)]
A3=So*(V-3-3+9/V-3+9/V+9/V-27/V^2)
A3=So*(-9+V+27/V-27/V^2)

A3/V=S3=0.5*So
So/V*(-9+V+27/V-27/V^2)=0.5*So
2*/V*(-9+V+27/V-27/V^2)=1
Multiply both sides by V^3
-18*V^2+2*V^3+54*V-54=V^3
1*V^3-18*V^2+54*V-54=0

Solve for V
V=14.54

Answer:
V=14.54 pints

Hopefully no mistakes


Cam

January 1, 2010 5:47 PM  
Blogger manjinder said...

Cam I've been following you for the last couple of days, given that I am still in high school I probably may some of this later but still your intelligence is outstanding, all I'm asking is how did you do it and is there anyway that I can reach your standards as well.

January 2, 2010 7:15 AM  
Anonymous Anonymous said...

Manjinder,

Thank you very much for the compliment. I probably don't deserve it.

The only advice I can give you is: work hard, ask lots of questions, and maintain a thirst for knowledge.

Good luck with your studies.

Cam

January 2, 2010 7:49 AM  

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