Question

The number of four digit telephone numbers formed by the digits is ( Note : 0 can be accepted in the first place ):

• A. ${10}^{14}{-}^{10}{p}_4$
• B. ${10}^4$
• C. ${}^{10}{p}_4$
• D. $9^4$

Answer 1

The correct option is C ${}^{10}{p}_4$

We have

Total number of telephone number is $=10$

Makes Telephone number is $4$ digits.

Then,

Number choosing ${}^{10}{p}_4$

Hence, this is the answer.