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

Ranjan made a profit of 25% when selling a TV set at Rs. 3000. If he now has to pay Rs. 500 more for the set, what should be his new selling price in order to make the same percentage of profit?

A cow was sold at 8% profit. If it were bought at 20% less and sold at 40% profit, then the owner would gain ₹ 640 more. Find the initial cost price of the cow.

If an item is sold for Rs. 270, there is a loss of 10 percent on it , then what will be the cost price of that item?

A man purchased a bed sheet for Rs. 450 and sold it at again of 10 % calculated on the selling price. The selling price of the bedsheets was 

A person bought pens at 25 for a rupee and sold at 15 for a rupee. What is his profit percentage? 

Cost of 36 pens and 42 Pencils is Rs 460. What is the cost of 18 pens and 21 pencils?