i think i get the problem now... "if Sam were twice as old as he is" 2S "he would be 40 years younger than Jim" 2S + 40 = J "if jim is 10 years younger than Sam" J = S - 10 "how old is Sam?" 2S + 40 = S - 10 S = 30 what's the OA? If 2S+40 = S-10... how is S=3...