Finding Discounts#!#Finding cost price/selling price, profit %/loss%

The selling price of one article after allowing a discount of 15 % on its cost price is same as the selling price of another article after allowing a discount of 25% on its cost price. If the sum of the cost price of both the articles is ₹640, then find the selling price of each article.

One-fifth of the cost price and one-sixth of the selling price are equal. Find the profit or loss percentage.

Cost price of A is twice the cost price of B. If the selling price of B is Rs.3600 and it is sold at the profit of 20%, then find the cost price of A.

Selling price of 25 articles is equal to cost price of 20 articles. Find profit/loss %.

Selling price of 33 articles is equal to cost price of 44 articles. Find profit/loss %.