Math Probability
posted by Anonymous on .
A certain state's lottery game, LOTTO, is set up so that each player pays $1 per ticket and chooses six different numbers between 1 and 20 inclusive. If the six numbers chosen match the six numbers drawn, the player wins the grand prize.
If a person buys one LOTTO ticket, what is his probability of winning the grand price?

20 x 20 x 20 x 20 x 20 x 20
You have 20 chances for each number and that happens for each draw...
you have 1 chance out of _________
Can you finish from here? 
Joe has assumed that the same number could be drawn more than once.
However,in most of these lotteries, some kind of drawing method is used, such as 20 differentnumbered pingpong balls, and the order that they are drawn does not matter.
Number of ways to draw 6 numbers from 20
is C(20,6) = 38760
so prob(winner) = 1/38760 
Thank You, Joe and Reiny for your help. I believe Reiny you use combination formula and I believe you are right, because the question does states that the order doesn't matter. Once again thanks to you both

I decided to add my name. This is my first time on here and I wanted to see what its all about...
another question I'm struggling with
If a person buys 1000 LOTTO tickets, what is his probability of winning the grand prize? 
Assuming that you don't play the same set of numbers and it is the same drawing. All you do is add the number of tickets bought to the top number so 1000/38760. Which is about a 2.5% chance of winning. If it is one ticket a game for a 1000 times. It stays 1/38760.