If a% is the first discount and b% is the second discount on the marked price of an article, then the equivalent single discount percentage is given by:

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?