Answer to Question #18300 in Combinatorics | Number Theory for akbar

Question

How many 3 digit positive even integers are there, such that all the digits are distinct from each other?
i want answer b4 sundayy plzzz

Answer 1

There are totally 4 possibilities. The last number is always even. The first can not be 0. So we have

1. odd odd even integer 5*4*5 = 100 integers in this case.

2. odd even even integer 5*4*4 = 80 integers in this case.

3.even odd even integer 4*5*4 = 80 integers in this case.

4.even even even integer 4*4*3 = 48 integers in this case.

308 integers of this type totally.