Question

A chemist mixes 4 liters of one acid solution with 10 liters of a 40% solution, resulting in a 30% acid solution. The table shows the amount of each solution used. What is the value of x, the acid concentration of the first solution?

Answer 1

The 4-liter acid material was a lower concentration than 40%. Call it 4 liters of x percent acid.

4x+10*40
————— =30
X+10