Question

Find the number of 4 digit numbers that can be formed using the digits 1,2,3,4,5 if no digits is no repeated
How many of these will be even?

Answer 1

Answer:

5 different numbers, 2 even

Step-by-step explanation:

Since we have 5 digits and they are non repeating we can use the permutation formula:

$P(n, k) = \frac{n!}{k!}, where k \leq n ; k, n \in \mathbb{N}$

It gives us the amount of ways to arrange k objects out of n objects without repetition, but order does matter.

In our case the amount of 4 digit numbers that can be formed using the digits from 1 to 5 is: $P(5, 4) = \frac{5!}{4!} = 5.$

And out of those 5, only 2 are even