With the four numbers of 2, 3, 4 and 5, many four digit numbers without repetition can be formed. What is the sum of all these four digit numbers

With the four numbers of 2, 3, 4 and 5, many four digit numbers without repetition can be formed. What is the sum of all these four digit numbers

In this technique, the total number of four digits is 4 × 3 × 2 × 1 = 24
So, because when you make up four digits, each number has the same chance
Then each number appears six times in the individual, ten, hundred and thousand digits
Then the sum is (2 + 3 + 4 + 5) × (1000 + 100 + 10 + 1) × 6 = 93324