Before going to the answer, let's first understand what a mark up is. The mark up is the amount that the seller will add to the purchase cost to the retail cost so that he can earn a profit. So the purchase cost of the television is 125 dollars, and the selling cost or retail cost of the television is 200 dollars. So what is the markup. Simply minus 125 dollars from 200 dollars and you will get the amount added to the purchase cost or simply the mark up. So 200 dollars - 125 dollars is 75 dollars. So 75 dollars is the markup that the merchant put on the television