Question

Which of the following is/are true for ${}^n{C}_r$ ?

• A.
• B.
• C. Both A and B
• D. None of these

Answer 1

The correct option is C

Both A and B

We know,
${}^n{C}_r=\frac{n!}{r!(n-r)!}$
${}^n{P}_r={}^n{C}_r\times r!,0$ <$r\le n$
${}^n{C}_r=\frac{{}^n{P}_r}{\underset{–}{|r}}$