# calculus

posted by
**Nasi**
.

A publisher prints and sells both hardcover and paperback copies of the same book. Two machines M and N are needed to manufacture these books. To produce one hardcover copy,machine M works 1/6 hours and N works 1/12 hours. For a paperback copy M and N work 1/15 and 1/16 hours respectively. Each machine maybe operated no more than 12 hours per day. If the profit is R12 on a hardcover copy and R8 on a paperback copy, how many of each type should be made per day to maximize the profit?