question: If Chester eats 3 eggs a day for 30 days and then increases it to 5 eggs a day for 30 days, how many dozens of eggs will Chester need for 60 days?
answer: He starts off eating 3 eggs a day for 30 days for a total of 3*30 = <<3*30=90>>90 eggs
  Then he increases it to 5 eggs a day for 30 days for a total of 5*30 = <<5*30=150>>150 eggs
  All total he will eat 90+150 = <<90+150=240>>240 eggs
  There are 12 eggs in 1 dozen and he will 240 eggs which is 240/12 = 20 dozen eggs
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