The number of possible combinations of a group of numbers is called permutations. A common example of permutations is the lottery. The odds of winning the Powerball are one in 195,249,054. That last figures comes from the total number of possible combinations the winning number might have. The formula for calculating permutations is complex, but Microsoft Excel simplifies this with either the Permut or Combin function.
Enter "=combin(numbers,draws)" in a blank cell if the draw order does not matter. Most lotteries not require the proper draw order, so the Combin function works for them. Replace "numbers" with the number of selectable numbers. Replace "draws" with the number of drawings. As an example, the Florida Lottery allows you to select six numbers, ranging from 1 to 53, and order is not important. Therefore, you would enter "=combin(53,6)" in a blank cell to calculate 22,957,480 possible combinations.
Enter "=permut(number,draws)" when order does matter. In the Florida Lottery example, if 1-2-3-4-6 was considered different than 6-5-4-3-2-1, then you would use the Permut function. Enter "=permut(53,6)" in the cell, resulting in 16,529,385,600 possible combinations.
Multiply functions when multiple conditions exist. As an example, the Powerball requires five numbers from 1 to 59, plus one number from 1 to 39. Therefore, you would enter "=COMBIN(59,5)*COMBIN(39,1)" in the cell to calculate 195,249,054 possible combinations.