Answer:
The house is 5 years old now
Step-by-step explanation:
Let the current age of the house be x
The mortgage still has 10 years left
This means that the mortgage will be completely paid off in 10 years time
Age of the house in 10 years time = x + 10
In 10 years time, the house wil be 3 times as old as it is now
The equation will, therefore, become:
x + 10 = 3x
Solve for x in the equation above to find the current age of the house
x + 10 = 3x
3x - x = 10
2x = 10
x = 10/2
x = 5
The house is 5 years old now