Ravi purchased two articles for Rs. 1,500 each. He sold them, gaining 6% on one and losing 4% on the other. His gain/loss percent in the whole transaction is:

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?