Question

This qusestion is from 11 from permutation and combination:
How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed

Answer 1

HIII........

YOUR ANSWER

9 ! / ( 9 - 4 ) !

9 ! / 5 !

(9* 8* 7 * 6* 5 !) / 5 !

3024.....

SO A FOUR DIGIT NUMBER CAN BE FOUND IF WE USE 3024 TIME.......WITHOUT REPEATATION.

THANKS