Carrie $($age $45)$ has been a teacher for the last $21$ years, Graham $($age $47)$ is a business executive. Carrie earns $$89,000$ per year and Graham earns $$235,000.$ Graham does not have a pension plan, but Carrie has a DBP$.$ They would like to retire in $17$ years and they think they will need an income of at least $60\%$ of what they currently earn. They have two daughters, age $9$ and $11.$ Carrie and Graham would like to save $$50,000$ for each child's education. Carrie and Graham are not great at managing their finances, but realize that they should pay off their debt before retirement. Carrie's car is fully paid for. Graham is leasing a luxury car. The current mortgage is at $4\%$ with $20$ years remaining on the amortization. When will the house be paid?