Answer:
0.000000004 = 4 hundred millionths probability Brent will win the jackpot.
Explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
In this question:
1 desired combination out of 258,890,850. So

9 places after the decimal point is hundred millionths
0.000000004 = 4 hundred millionths probability Brent will win the jackpot.