“My Dad is three times my age,” declared Dimple,”‘but he’s the square of my younger brother’s age. I’m twice as old as my younger brother.” What age was his younger brother?
Answer
His younger brother was 6.
Let his age be x, Dimple’s age be y, and his father’s age be z.
Then z=3y, z=x2, y=2x. So 6x=x2 and x=6.