Solution to puzzle 78

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 Here is the solution to puzzle 78

Solution:

  1. Let us say her age now is x.
  2. So 3 years later her age is x+3. 3 times that is 3x+9.
  3. Her age 3 years ago is x-3. 3 times that is 3x-9
  4. When you subtract them, you get 3x+9 - (3x-9) = 18.
  5. She says that is her age. Her age is 18.

 

 

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