Question

How many numbers can be formed from the digits 1,2,3,4 when the repetition is not allowed

• A. ${}^4{P}_4$
• B. ${}^4{P}_3$
• C. ${}^4{P}_1{+}^4{P}_2{+}^4{P}_3$
• D. ${}^4{P}_1{+}^4{P}_2{+}^4{P}_3{+}^4{P}_4$

Answer 1

The correct option is A ${}^4{P}_4$

Digits: $1,2,3,4$

If repetition is not allowed, then,

No. of digits formed ${=}^4{P}_4$.