human
Cynthia has three children whose ages add up to 35. Matthew is two years older than Rebecca and four years younger than Freddy. How many years old is Freddy?
assistant
Define a variable ** Let A be Matthew’s age.
How old is Rebecca? ** Rebecca is A - 2 years old.
How old is Freddy? ** Freddy is A + 4 years old.
Write an equation ** Their ages add up to 35, so A + A - 2 + A + 4 = 3A + 2 = 35.
Simplify ** Therefore, 3A = 35 - 2 = 33.
How old is Matthew? ** Matthew is A = 33 / 3 = <<33/3=11>>11 years old.
How old is Freddy? ** Thus, Freddy is 11 + 4 = <<11+4=15>>15 years old.
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