question: In 10 years, Melanie will be 18 years old. In how many years will her age be thrice her present age?
answer: Melanie's present age is 18 - 10 = <<18-10=8>>8.
  Thrice Melanie's present age is 8 x 3 = <<8*3=24>>24.
  So, she will be thrice her present age in 24 - 8 = 16 years.
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