math help pls!
posted by BreAnna on .
A lottery is set up in which players pick six numbers from the set 1, 2, 3, ... , 39, 40. How many different ways are there to play this lottery? (In this game the order in which the numbers are picked does NOT matter.)

When the order does not matter, the number ways of choosing the lottery can be calculated using combinations, or C(n,r), read as "n chose r". C(n,r) is defined as n!/(r!(nr)!), similar to the evaluation problem of your other post.
So in the case of the lottery problem, n=40, r=6, and order does not matter. So "40 choose 6" gives the answer.
Evaluate "40 choose 6" the same way as the other problem:
40!/(6!(406)!)=....
Read the following link for more detailed information:
http://en.wikipedia.org/wiki/Combination