Question

A 12 liter solution is `33(1)/(3)`% acid. How much water must be added to get the solution having 20% acid?

Answer 1

Let x be the water added
then,
12(33.33%) = 20%(x + 12)
⇒ 12 x 0.3333 = 0.2(x + 12)
⇒ 3.999 = 0.2x + 2.4
⇒ 0.2x = 1.596
⇒ x = 7.95It = 8It
Approximately, 8 litres of water nust be added.