If Andrew is randomly selecting a digit between 1 and 9 then he has a 44% chance of picking an even number. As he increases the amount of numbers he chooses from, the probability will increase every time an even digit is added.
For Example, if Andrew chose between 1 and 5 he could choose either 2 or 4. This gives him a 2/5, or 40%. chance of getting an even number. But if he instead chooses between 1 and 6, he now has 2, 4, and 6 to choose from. This increases his probability to 3/6 or 50%. And this will happen every time Andrew chooses between a set of numbers that ends in an even number
