ANSWER:
1820 different ways
STEP-BY-STEP EXPLANATION:
We can use here combination rule for selection:
[tex]_nC_r=\frac{n!}{r!(n-r)!}[/tex]In this case n is equal to 16 and r is equal to 4, therefore, replacing and calculating the number in different ways, there:
[tex]\begin{gathered} _{16}C_4=\frac{16!}{4!(16-4)!}=\frac{16!}{4!\cdot12!} \\ \\ _{16}C_4=1820 \end{gathered}[/tex]So in total there are 1820 different ways Rudy can choose 4 pizza toppings.
