Dale has written too many checks and his bank balance is -42.68. The bank will charge him an overdraft fee of $25. How much does he need to deposit so that his bank balance will be $50?

The are 39,070,080 different ways the DJ can play the first 6 songs.

We will use the Fundamental Counting Principle to find the answer. Simply determine the number of choices for each position and multiply.

For the first choice there are 21 choices. Then, the number is reduced by 1 each time.

So to get the answer, we have to multiply the numbers below:

21 x 20 x 19 x 18 x 17 x 16