Formulate but do not solve the problem. You will be asked to solve these
problems in the next section.
Lawnco produces three grades of commercial fertilizers. A 100 -lb bag of
grade-A fertilizer contains 18 lb of nitrogen, 4 lb of phosphate, and 5 lb of
potassium. A \(100-\mathrm{lb}\) bag of grade-B fertilizer contains \(20
\mathrm{lb}\) of nitrogen and \(4 \mathrm{lb}\) each of phosphate and potassium.
A \(100-\mathrm{lb}\) bag of grade-C fertilizer contains 24 lb of nitrogen, 3 lb
of phosphate, and 6 lb of potassium. How many \(100-\mathrm{lb}\) bags of each
of the three grades of fertilizers should Lawnco produce if 26,400 lb of
nitrogen, 4900 lb of phosphate, and \(6200 \mathrm{lb}\) of potassium are
available and all the nutrients are used?