First, calculate how many five digits 12358 can arrange: 5*4*3*2* 1= 120.

Question 1: Calculate how many odd numbers there are, that is, numbers with a mantissa of 1.3.5:

A number with a mantissa of 1 is 4*3*2* 1=24.

Numbers with a mantissa of 3 are 4*3*2* 1=24.

The digits with a mantissa of 5 are 4*3*2* 1=24, of which 72 digits are odd.

So the odd probability is 72/ 120=60%.

There is another solution to the problem 1. There are only five possibilities for the mantissa of five digits: 1.2.3.5.8, among which there are three odd numbers and two even numbers, so the probability of odd numbers is 3/5=60%.

Question 2: If it is less than 230 million, then there are 4 * 3 * 2 * 1 digits = 24.

The tens of thousands of digits of 2 must be 1, 3*2* 1=6 digits.

There are 24+6=30 and the number is less than 23000.

The probability of less than 23000 is 30/ 120=25%.