In four years, Peter will be twice as old as Harriet. If Peter's age is currently half of his mother's age, who is 60, how old is Harriet now?
How old is Peter now? ** If Peter's age is currently half of his mother's age, who is 60, Peter is 1/2*60 = <<30=30>>30 years old.
How old will Peter be in four years? ** In four years, Peter will be 30+4 = <<30+4=34>>34 years old.
How old will Harriet be in four years? ** Since Peter's age in four years will be twice Harriet's age, Harriet will be 34/2 = <<34/2=17>>17 years old in four years.
How old is Harriet now? ** Currently, Harriet is 17-4 = <<17-4=13>>13 years old.
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