Help with an Algebra question

Question

In one​ lottery, a player wins the jackpot by matching all five numbers drawn from white balls​ (1 through

45​) and matching the number on the gold ball​ (1 through 31​). If one ticket is​ purchased, what is the probability of winning the​ jackpot?

Answer 1

number of sets of 5 numbers in 1 - 45 is 45C5 = 1221759

number of winning sets of 5 numbers is 1

------

P(pick the proper set of 5 numbers) = 1/1221759

P(correct number on gold ball) = 1/33

= (1/1221759)(1/33)

= 1/40,318,047

probability of winning the​ jackpot is 1/40,318,047