<span>The 6 playing cards may be arranged into 6 factorial (!) combinations, since the order of the cards does not matter, and since for each card we select, there is now one less card to choose from (for example 6 cards to start, then 5 to choose from, then 4, etc.)
So the number of combinations is 6! = 6 x 5 x 4 x 3 x 2 x 1 = 720 combinations.</span>
To find the sales tax multiply the purchase price by the sales tax rate. Remember to convert the sales tax rate from a percent to a decimal number. Once the sales tax is calculated, it is added to the purchase price. The result is the total cost—this is what the customer pays.
