Question

using the digits 1,4,5,9 wat are all the differnt 4-digits number u can write if no digit can be reapeted in a number

Answer 1

It is a probably type problem. My hint is to look up so examples in probability. Also try and work on your spelling.

(wat) needs to be (what)
(u) needs to be (you)
(differnt) needs to be (different)

Answer 2

i no how to spell i just to lazy to type it

Answer 3

i think it's 24. if im not mistaken.it's 4! or 4p4 right?

Answer 4

Yes, this is a permutation. 4p4, which is 24.

Answer 5

ive never seen this notation before, 4! = 4p4? so 5! = 5p5?

Answer 6

The permutation is:
\[\frac{n!}{(n-k)!}\]

Since n = k = 4, you have 0! in the denom, which is simply 1. Therefore 4!

Answer 7

npk or kpn?