IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => University => Topic started by: XIII_BD on February 12, 2010, 10:49:14 am

Title: Math Q
Post by: XIII_BD on February 12, 2010, 10:49:14 am

How many gallons of distilled water must be mixed with 50 gallons of 30% alchohol solution, to obtain a 25% solution.

pls help me out here u guys....

Title: Re: Math Q
Post by: astarmathsandphysics on February 12, 2010, 12:19:07 pm

There are 15 gallons water to start.Suppose x gallons are added, the amount of solution is 50+x
(15)/(x+50)=0.25
15=0.25x+12.5
0.25x=2.5 so x=10

Title: Re: Math Q
Post by: SGVaibhav on February 13, 2010, 08:39:03 am

omg this looks so easy, but its still hard :P

Title: Re: Math Q
Post by: Saladin on February 13, 2010, 08:56:04 am

dude, that integration question that u posted, it was soooo damn funny

i cud not stop laughing man

hehe

Title: Re: Math Q
Post by: SGVaibhav on February 13, 2010, 09:16:47 am

Quote from: The Dude 321 on February 13, 2010, 08:56:04 am

dude, that integration question that u posted, it was soooo damn funny

i cud not stop laughing man

hehe

mee???
lol which one??

Title: Re: Math Q
Post by: Saladin on February 13, 2010, 05:16:41 pm

The integration question like where u cud not get why it was 2 instead of 4, and it was basically cuz u 4got to sq.rt.

Title: Re: Math Q
Post by: nid404 on February 16, 2010, 05:33:51 pm

This is like serial dilutions......we have it in bio

50 gallons of 30% acohol solution
15 gallons of alcohol
v1c1=v2c2
50X30=V2X25
V2=60gallons

So 10 litres of water to be added....
Actually the same thing as astar but mabe this should make it easier