Take any two numbers from the four numbers 1, 2, 3 and 4, and calculate the probability that one of the two numbers is odd and the other is even

Take any two numbers from the four numbers 1, 2, 3 and 4, and calculate the probability that one of the two numbers is odd and the other is even

Take out two numbers, one is odd, one is even = 2x2 = 4
There are 10 kinds of numbers taken from 1, 2, 3 and 4
So probability = 4 / 10 = 0.4