we broke it down to smaller numbers (1-9 with 1 digit number, then 1-9 with double digit number, etc.).
you had to eliminate all the single digit and double digit numbers as you wanted a triple digit number.
he can work out what happens when n=1,10, 100, then n.
I don't understand any of the above, or how it relates to lottery odds.
As for how to calculate the odds of a lottery, it depends on the lottery, and how it's set up. Let's use Powerball as an example, since it's the most common.
Powerball uses 5 numbers 1 - 59, then the sixth number (the powerball) from a different set of numbers 1 - 35, so that the powerball number can be the same as one of the first five.
Imagine the balls are all being drawn one by one. The first ball has a 5 in 59 chance of matching one of your selections, because there are 59 balls in the drum, and you've selected 5. Simple enough.
The next ball coming out is one of only 58, and assuming you matched the first ball, you've only got four left, so it's 4/58.
Next ball is one of 57, and you have 3 left.
And so on...
Then comes the powerball, which has an unalterable odds of 1 in 35.
So, the odds of winning the powerball jackpot are 5/59 x 4/58 x 3/57 x 2/56 x 1/55 x 1/35.
Looking at those numbers, it should then be pretty obvious how to construct the formula.
