Question

evaluate the following expression. It's pressure answer to fraction or decimal rounded to four decimal places.

Answer 1

$\begin{gathered} nPr=\frac{n!}{(n-r)!},\text{ solve for 10P8} \\ 10P8=\frac{10!}{(10-8)!} \\ 10P8=\frac{10!}{2!} \\ 10P8=\frac{3628800}{2} \\ 10P8=1814400 \\ nCr=\frac{n!}{r!(n-r)!},\text{ solve for 10C7} \\ 10C7=\frac{10!}{7!(10-7)!} \\ 10C7=\frac{10!}{7!\cdot3!} \\ 10C7=\frac{10\cdot9\cdot8}{3\cdot2} \\ 10C7=120 \\ \\ \frac{10P8}{10C7}=\text{?} \\ \frac{10P8}{10C7}=\frac{1814400}{120} \\ \frac{10P8}{10C7}=15120 \end{gathered}$