The same is not true of a computer. Even common sense things have to be programmed into it. A computer is simply a machine. Now let us do some simple arithmetic. There is no trick to the question.
Age is computed by subtracting birth year from current year.
That is how a computer in your bank may compute the age of your loan. You are human. You can make assumptions whenever the data appears insufficient. A computer does not assume anything, unless it has been programmed to assume it. To make matters worse, some computers have been programmed to know that age cannot be negative.