question: Jean is two years older than Mark.  Two years ago Mark was 5 years older than half Jan's age.  If Jan is 30 how old is Jean?
answer: 2 years ago Jan was 30-2=<<30-2=28>>28 years old
  So Marks age two years ago was 5+28/2=<<5+28/2=19>>19 years old
  Mark is now 19+2=<<19+2=21>>21 years old
  So Jean is 21+2=<<21+2=23>>23 years old
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