A shopkeeper makes a 10% profit on one-third of his items, a 17% profit on another one-third, and a 9% loss on the remaining items. Find his overall net profit percentage.

A company considers hiring an extra machine for $150 per day to produce additional units. If the additional throughput contribution generated from producing these units on the machine is $390, by how much will total profit increase?

If the cost price of an article is 85 times its selling price, what is the loss percentage?