Write the numbers 1, 2, 3, 4 and 5 on the five cards, mix them and arrange them in a row. What is the probability that the number can be divided by 2 or 5? Why is the last place divisible by 2 only 2 or 4? There are 48 kinds of 2 * 4 The last place divisible by 5 can only be 5, total = 24 kinds How did you get here?

Write the numbers 1, 2, 3, 4 and 5 on the five cards, mix them and arrange them in a row. What is the probability that the number can be divided by 2 or 5? Why is the last place divisible by 2 only 2 or 4? There are 48 kinds of 2 * 4 The last place divisible by 5 can only be 5, total = 24 kinds How did you get here?

This is a permutation problem. 12345 and 23451 are two different permutations, so there are 5 permutations. 5 digits can be divided by 2, and the last digit must be 2 or 4. If the last digit is 2, we only need to consider the permutation of the first 4 digits: 4! Similarly, if the last digit is 4, we only need to consider the permutation of the first 4 digits: 4! So, there are 2 × 4