Answer:
Step-by-step explanation:
Let x represent the volume in mL of 33% solution needed. Then 70-x is the volume of 19% solution required. The total amount of solute is ...
0.33x + 0.19(70 -x) = 0.29(70)
0.14x = 70(0.29 -0.19)
x = 70(0.10/0.14) = 50
50 mL of 33% solution should be mixed with 20 mL of 19% solution to get the desired mix.