My father is currently 13 times as old as my daughter. Next year, my father will be 11 times as old as my daughter. How many years old is my father now?

Question

My father is currently 13 times as old as my daughter. Next year, my father will be 11 times as old as my daughter. How many years old is my father now?

Answer 1

Let x = your father's age and y = your daughter's.  This year:

 

x = 13y

 

Next year:

 

x+1 = 11(y+1)

 

x = 11y + 10

 

Now let's substitute 13y for x:

 

13y = 11y + 10

 

Solve for y, your daughter's age.  Once you have y, x (father's age) = 13y.