Mr. Klinker is 35 and his daughter is 10. In how many years will Mr. Klinker be twice as old as his daughter?

Question

Mr. Klinker is 35 and his daughter is 10. In how many years will Mr. Klinker be twice as old as his daughter?

Answer 1

You can try to do this empirically (trial & error):

add 10 years to each--he's 45, she's 20 <---not quite right

add 15 to each -- he's 50, she's 25..by George, that's it.  15 years from now!