A merchant advertises $10 \%$ off on the items bought from his store. The total discount got by a customer who bought a cooker worth $Rs.\,650,$ a heater worth $Rs.\,500$ and a bag worth $Rs.\,65$ is (in $Rs.$)

The list price of an article at a showroom is $Rs.\, 2000$ and it is being sold at successive discounts of $20 \%$ and $10 \% .$ Its net selling price will be (in $Rs.$)

The profit earned by selling an article for $Rs.\, 900$ is double the loss incurred when the same article is sold for $Rs.$ $450 .$ At what price should the article be sold to make $25 \%$ profit in $Rs.$?

Sudeep buys two $CDs$ for $Rs.\,380$ and sells one at a loss of $22 \%$ and the other at a gain of $12 \%$. If both the $CDs$ are sold at the same price, then the cost price of two $CDs$ is (in $Rs.$)

By selling $90$ pens for $Rs.\, 80$ a man loses $20 \%$. What should be the selling price (in $Rs.$) of $90$ pens for $20\%$ profit?