Question

Find the value of 20C17​

Answer 1

Answer:

what question

Step-by-step explanation:

ask proper questions

Answer 2

Answer:

The value of  $^{20} C_{17}=1140$

Step-by-step explanation:

Given $^{20} C_{17}$

Different combinations of $n$ objects taken $r$ at a time is given by $^{n} C_{r}$.

                                  $^{n} C_{r}=\frac{n!}{r!(n-r)!}$

                                $^{20} C_{17}=\frac{20!}{17!(20-17)!}$

                                          $=\frac{20!}{17!(3)!}=\frac{20\times 19\times 18}{3\times 2}$

                                          $=10\times 19\times 6=1140$

Therefore, the value of  $^{20} C_{17}=1140$