Mario earned three times as much money last year as his wife Elena. The total amount that the two earned was $11,000. How much money did Mario earn?

Let Mario's earnings be represented by m.


m + m/3 = $11,000
  (4/3)m = $11,000
  m = 3/4*$11,000
  m = $8,250
Mario earned $8,250 last year.