Math word problem 4 ?

Question

110. A chemist working on a flu vaccine needs to mix a 10% sodium-iodine solution with a 60% sodium-iodine solution to obtain a 50-milliliter mixture. Write the amount of sodium-iodine in the mixture, S, in milliliters, as a function of the number of milliliters of the 10% solution used, x. Then find and interpret S(30).

Answer 1

S(x) = 0.1x + 0.6(50 - x)

x is the amount of solution with 10% concentration

(50 - x) is the other amount .. . .  since they must add up to 50 ml.