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17. What figure should replace the question mark?
  IQ test. Fast and free online iq test # 1 with answers and solutions. Question # 17. What figure should replace the question mark?
 

Explanation:
Upper number = (lower left number + middle left number) - (lower right number + middle right number) ÷ 2. (3 + 8) - (7 + 5) ÷ 2 = 5; (9 + 7) - (4 + 8) ÷ 2 = 10; (11 + 2) - (6 + 12) ÷ 2 = 4.