Problema Solution
A chemist needs 90 milliliters of a 72% solution but has only 68% and 77% solutions available. Find how many milliliters of each that should be mixed to get desired solution.
Answer provided by our tutors
Let x = amt of 77% solution required
Let y = amt of 68% solution required
:
"A chemist needs 90 milliliters of a 72% solution"
x + y = 90
y = (90-x); use this form for substitution
:
" but has only 68% and 77% solutions available."
Use the decimal equiv here
.77x + .68y = .72(90)
.77x + .68y = 64.8