actually , it's 5 white number 1-55, and a separate red power ball 1-42. Also the numbers can be in any order so it's a combination not a permutation. using the equation nCr = n!/(r! * (n-r)!)
just for the 5 white number is 55C5 = 3478761
for the power ball number 42C1 = 42
3,478,761 * 42 = 146,107,962
which means there is a 1/146,107,962 chance to win the powerball jackpot, which means to be certain you need about $147 mil to buy all combinations