A shopkeeper believes in running his business on the sentiments of market i.e., quick response to the demand-supply relationship. He starts every morning by selling product X at Rs 500 for the first hour. If the number of customers for any hour is more than 10, he will increase the price by Rs 10 over the price of the previous hour. If less than 10, he will decrease the price by Rs 10 over the previous hour. If it is equal to 10, then he will maintain the same price level of the previous hour. CP of product X is Rs 440.
If the customer for the first four hours are 15, 10, 6 and 12, then find the profit made by the shopkeeper.