How much water must be added to 12 L of a 40% solution of alcohol to obtain a 30% solution?

Question

anonymous · Answer

0.4(12)=4.8L of alcohol now
This means 7.2 L of water.
(7.2+x)=0.7(12+x)
7.2+x=8.4+0.7x
0.3x=1.2
x=4
x is the amount of water added.

anonymous · Answer

Fool can i get your help

anonymous · Answer

Sure tinkerbell, how can I help you?

anonymous · Answer

im trying to check 20 math questions and see if i have the right answers

anonymous · Answer

20 is a big number :(

anonymous · Answer

i know but it will go quick i promise

lalaly · Answer

lol fool has time:P

anonymous · Answer

i have it done im just checking to see if i have them right

anonymous · Answer

lol, lala and diya would certainly  help you :P

anonymous · Answer

okay sure tinker post them.

lalaly · Answer

hehehe

anonymous · Answer

post them here or do a new post

anonymous · Answer

ok

anonymous · Answer