Question

In how many ways a four digit even
number can be formed by using the
digits 4, 5, 9, 8 exactly only once?
A
24
B
12
C С
6
D
18​

Answer 1

In case of an even number unit digit can be 4 or 8 . So for unit digit you've 2 ways.

Now suppose you've putted 8 on the unit digit, you're left with 3 numbers so you've respectively 3,2 and 1 ways.

Total ways

2*3*2*1 =12 ways .

Option b is correct answer.