Verified answer

let the volume of the 10% solution be a and the volume of the 20% solution be b

a + b = 500mls

16% of 500 ml = 80mls

10a/100 + 20b /100 = 80

a + 2b = 800 .....(1)

a + b = 500 .......(2)

(1) - (2)

b = 300ml

therefore a + 300 = 500

a = 200ml

Let x = the 10%

then 500-x = the 20%

Change the percents to decimals

0.10x + 0.20(500 -x) = 0.16(500)

0.10x + 100 - 0.20x = 80

-0.10x = -20

x = 200

so 200 mL of the 10% solution and 300 mL of the 20% solution

doode i hate solution equations :P

first group the stuff into a table

% solution amount solution amount (m)

1

2

Final Mix

put the numbers into the correct places

and then put them together into an equation and solve