A shopkeeper bought an article for ₹(2x + 200), marked it up by 60%, and sold it at a 20% discount. If the profit earned is ₹(x - 23.2), find the selling price of the article when it is sold at a 20% profit.

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?