Solve Using a System of Two Equations in Two Unknowns

Multiple Choice

Solve using a system of two equations in two unknowns.
-A chemist needs 100 milliliters of a 70% solution but has only 66% and 86% solutions available. Find how many milliliters of each that should be mixed to get the desired solution.

A) 90 milliliters of 66%; 30 milliliters of 86%
B) 90 milliliters of 66%; 20 milliliters of 86%
C) 80 milliliters of 66%; 20 milliliters of 86%
D) 20 milliliters of 66%; 80 milliliters of 86%