To sell 300 notebook and 120 pens quickly, a store decided to crete two types of gifts sets. one set in to include 2 notebook and 1 pen, and the other will consist of 1 pen and 3 notebooks. first set will be sold for $8 while the second is to cost $11.50 it is unprofitable for the store to sell less than 20 of any gift set how many gift sets of each type does store need to sell to obtain the biggest possible income