Given that
The number is drawn from white balls = 5
Explanation -
The number of sets of 5 numbers in (1 - 42) is = 42C5 = 850668
And the number of winning sets of 5 numbers is 1.
P(pick the proper set of 5 numbers) = 1/850668
P(correct number on gold ball) = 1/31
So the required probability will be,
P = (1/850668)(1/31)
P = 1/ 26370708
Hence the probability of winning the jackpot is 1/26370708.