Question

Show an equation and a solution for the problem. How much water must be added to 12 L (liters) of a 40% solution of alcohol to obtain a 30% solution?

Answer 1

let x be the total volume after adding the water
then as the amount of alcohol stays constant
12 * 0.4 = x * 0.3
x = 4.8 / 0.3 = 16 litres

so amount added = what?

Answer 2

The amount of alcohol in the solution is 40% of 12L, or
0.40*12L=4.8L
If that amount is to be 30% of the expected volume (in liters) of 12+x,
then
0.30*(12+x)=4.8
3.6+0.30x=4.8 -->
0.30x=1.2 -->
x=1.2/0.30 -->
x=4.0
You need to add 4.0L water.

Answer 3

volume was 12 now its 16

Answer 4

- as jackelyn said

Answer 5

thanksss

Answer 6

yw