Question

You purchase an item to sell in your store. The item costs you $6.45. You mark the item up 20%, but later run the item on sale at 5% off the marked price.If your customer must pay 6% sales tax, what will be the total amount paid by the customer for the item?

Answer 1

You mark it up 20% Price + 20% = p + 20/100p = p (1 + 0.20 ) = 1.2 p 
6.45 * 1.2 = 7.74

You take off 5% which by the same reasoning (almost) means p/1.05
7.74 / 1.05 = 7.37

Now you need a sales tax
7.37 * 1.06 = 7.81 dollars.

Answer: The customer paid 7.81 <<<<=====