Question

How to evaluate 8P7?

Answer 1

`40320`

Explanation:

`"using the definition of "^nP_r=(n!)/((n-r)!)`

`"where "n! =n(n-1)(n-2)...... xx1`

`rArr^8P_7=(8!)/(1!)`

`color(white)(xxxxx)=(8xx7xx6xx5xx4xx3xx2)/1`

`color(white)(xxxxx)=40320`