How many different three digit numbers can be written using digits 1,2,3,4,5 without any repeating digits? you.

1st Method:

The 1st digit can be written in 5 ways
The 2nd digit can be written in 4 ways (since 1 already gone and no repetition)
The 3rd digit can be written in 3 ways (since 2 already gone and no repetition)

Total number of ways = 5x4x3 = 60 ways

2nd Method : Permutation  (since ORDER MATTERS) of 3 digits chosen among 5 (with no repetition)

⁵P₃ = (5!)/(5-3)! = (5!)/(2!) = 60 ways

That is so true, i can’t believe how true this is