When no discount is given selling price is the same as marked price. The reduction made on the marked price of an article is called the discount. Divide the list price by 2 to get the discount.
Divide the list price by 5 to get the discount.
So 25 of 200 is 50. Multiply the resultant number by 100. Subtract the post-discount price from the pre-discount price. Be proud of your mathematical abilities.