Question

Six examination papers are to be set in a certain order not to be disclosed. It is discovered that one order has been leaked out. The number of ways that their order can be changed is

• A. ${}^6{P}_1$
• B. ${}^6{C}_1$
• C. $216$
• D. $719$

Answer 1

The correct option is D $719$

Number of orders of paper is $6!=720$
Since one order is leaked out, number of ways $=720-1=719$