Cost of 18 shirts and 45 trousers is Rs 68,400. What is the cost of 10 shirts and 25 trousers?

Oranges are bought at 7 for Rs. 3. At what rate per hundred must they be sold to gain 33 % ? 

A shopkeeper marked an article 75% above the cost price and sold it after a discount of 50%. Find the cost price of the article if he had a loss of Rs. 156.

There is 10 % loss if a watch is sold for Rs 1440/-. At What price it is to be sold to get 15 % profit. 

When Vijay sells 12 pens, he gains the selling price of pens. Calculate his % profit?

Naresh purchased a TV set for Rs. 11,250 after getting a discount of 10 % on the labeled price. He spent Rs. 150 on transport and Rs. 800 on installation. At what price should it be sold so that the profit earned would have been 15 % if no discount was offered? 

By a selling basket for Rs. 19.50, a shopkeeper gains 30 %. For how much should he sell it to gain 40 %?