This is a problem based on permutations. We must select four jobs among ten jobs and see how many arrangments can be made.
The formula for the number of permutations is:
[tex]P(n,r)=\frac{n!}{(n-r)!}.[/tex]Where:
• n = total number of jobs = 10,
,• r = number of jobs to be selected = 4.
Replacing these data in the formula above, we get:
[tex]P(10,4)=\frac{10!}{(10-4)!}=\frac{10!}{6!}=\frac{10\cdot9\cdot8\cdot7\cdot6!}{6!}=10\cdot9\cdot8\cdot7=5040.[/tex]Answer5040