Ramesh claims that he is selling onions at Rs. 36 per kg, which costs him Rs. 40 per kg, but he gives 800 grams instead of 1 kg. Find Ramesh's percentage gain or loss.

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?