SOLUTION
Notice that there are 5 total topings
Since Helen is to select three topings then order does not matter
Hence the total number ways can be determined using combination rule:
That is:
[tex]_5C_3=\frac{5!}{(5-3)!3!}[/tex]This gives:
[tex]\begin{gathered} _5C_3=\frac{5\times4\times3!}{2\times1\times3!} \\ _5C_3=10 \end{gathered}[/tex]Therefore there are 10 ways Helen can combine the topings:
The topings are
pepperoni(P), sausage(S), ham(H),
mushroom(M), and onions(O)
The chart is shown:
