Question

How many six-digit passwords can you create if you use only numbers 1,2,3,4,5,6,7,8,9 without repetition?

Answer 1

60480

Explanation:

total number (n) = 9

r = 6

9P6 = 9!/(9-6)!

= 9×8×7×6×5×4×3!/ 3!

= 3! cancels out

= 9×8×7×6×5×4

= 60480