In a family of four, the mother is three times as old as her daughter. In 12 years, the mother will be twice as old as her daughter. How old is the daughter right now?
12 years old
Let the daughter's age be $D$ and the mother's age be $M$. We have $M = 3D$ and $M + 12 = 2(D + 12)$. Substitute $3D$ for $M$: $3D + 12 = 2D + 24$. Subtracting $2D$ and 12 gives $D = 12$. The daughter is currently 12.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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