Question

Show an equation and a solution. How much pure antifreeze must be added to 12 L of a 40% solution to obtain a 60% solution. (Remember that pure antifreeze is 100% = 1.)

Answer 1

6 litres because ...
12/40 = 1 ratio them x 60 for 60% which is 18 and since you have 12l already just do 18-12 = 6