The number of ways to select 20 out of 80 is $\binom{80}{20}$. The player needs to select 3,4, or 5 of these AND the rest from the remaining 60 numbers: $\binom{20}{3} \times \binom{60}{17} + \binom{20}{4} \times \binom{60}{16} +\binom{20}{5} \times \binom{60}{15}$. Can you sort out the rest?