Answer:
Ruby should go to college.
Explanation:
Ruby is currently 50 years old and earning $50,000 per year.
She would like to retire at 67.
She is thinking of going back to college, to complete a graduate degree.
After completing a graduate degree from the college she would earn $55,000.
The total cost of a graduate degree is $75,000.
Ruby still has 17 years to work and earn.
Her income will increase by $5,000 after college
The increase in income earned after college until retirement
= $5,000 17
= $85,000
Since the increase in income is greater than the cost of going to college, Ruby should go to college.