Question

(d) 13. The total number of 9 digit numbers of different digits is (a)10.9!(b) 8.9! (c) 9.9! (d) none of these .​

Answer 1

Answer:

(c)9.9!

Step-by-step explanation:

Total number of digits =10

i.e. 0,1,2,3,4,5,6,7,8,9

require 9 diffrent number

0 can not be placed in first place

= first place can be filled in 9 ways

and the rest 9 blank with 9 digits in 9! ways

total ways = 9×9!