Profit And Loss...

A sweet-seller declares that he sells sweets at the cost price. However, he uses a weight of 800 g instead of 1 kg. What is his percentage profit?

Beetel is a telephone manufacturing company. It has a target of 18% gain by selling 1,000 sets. But to some buyers, it sells at cheaper prices. It sells some at a gain of 25% and the rest at a gain of 15% and achieves its target. How many sets does it sell, respectively?

A man sells an article at a gain of 10%. If he had bought it at 10% less and sold it for Rs. 132 less, he would have still gained 10%. Find the cost price of the article.