ASTQB Exam CTAL Topic 1 Question 24 Discussion

A software company developed a software application for a Life Insurance Company. The testers of the software company were given the release to test. The software application calculates the annual life insurance cost based on customers' age. Life insurance cost is as follows per year;

# Age 18 or less: US $ 300

# Age over 18 or less than 70: US $ 500

# Person has to be at least 1 year old to purchase insurance

If a customer enters any other age, the software prints an error message. The Application accepts only positive integer values (no decimals). Given above scenario, how many valid test cases at minimum can you derive using equivalence partitioning?