A business man sold two flats for Rs. 8,25,000 each. On one he gains 9% while on the other he loses 9%. How much is his net gain or loss percentage in the whole transaction?

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?