75 65 85 55 45 85 35

• A. 25 75
• B. 85 35
• C. 25 85
• D. 35 25
• E. 25 15

Answer: (C)

This is a simple subtraction series in which a random number, 85, is interpolated as every third number. In the subtraction series, 10 is subtracted from each number to arrive at the next.