40 litres of 60% concentration of acid solution is added to 35 litres of 80% concentration of acid solution. What is the concentration of acid in the new solution?

Solution (By Examveda Team)

$$\eqalign{ & {\text{I}} \to \frac{{40 \times 60}}{{100}} = 24 \cr & {\text{II}} \to \frac{{35 \times 80}}{{100}} = 28 \cr & {\text{Acid }}\% = \frac{{52}}{{75}} \times 100 = 69\frac{1}{3}\% \cr} $$