When Vijay sells 12 pens, he gains the selling price of pens. Calculate his % profit?

By selling a pen for Rs 105 there is a loss of 30%. At what price (in Rs) the pen must be sold in order to gain 30%?

Naresh purchased a TV set for Rs. 11,250 after getting a discount of 10 % on the labeled price. He spent Rs. 150 on transport and Rs. 800 on installation. At what price should it be sold so that the profit earned would have been 15 % if no discount was offered? 

Sujatha sold 75% of her goods at a profit of 24% and the remaining at a loss of 40%. What is her gain/loss percentage on the whole transaction?

A dishonest dealer marks up the price of an article by 15% and gave a discount of 20%. He also uses 900gm instead of 1000gm. Find his profit percent.

The cost price of an article is 480. If it is to be sold at a profit of 6.25 %, how much would be its selling price? 

If a man estimates his loss as 20% of the selling price, then his loss percent is:

A vacuum cleaner was marked at 30% above the cost price and a discount of 24% was given on its marked price. What is the profit/loss percentage?