The average of five numbers is 18. If one of the numbers is removed, the average of the remaining four numbers is 16. What number was removed?

✓ Correct Answer: Option C

The sum of the five numbers is 5 × 18 = 90. After one number is removed, the sum of the remaining four numbers is 4 × 16 = 64. The removed number is the difference between these sums: 90 - 64 = 26.