Question

A passenger train has tickets available for 12 window seats and 8 aisle seats . The next person to buy a ticket will randomly assigned to one of those seats what is the probability that the next person will be assigned to an aisle seat?

Answer 1

.4
the ratio of aisle seats to total seats is 4/10

Answer 2

The answer is 2/5.  There is an 8/20 chance that the next person will receive a aisle seat. You simplify that. 8/20 becomes 2/5.