The average (arithmetic mean) of 5 numbers is 18. If one of the numbers is removed, the average of the remaining 4 numbers becomes 16. What was the value of the number removed?
✓ Correct Answer: Option D
The sum of the original 5 numbers is 5 * 18 = 90. The sum of the remaining 4 numbers is 4 * 16 = 64. The removed number is 90 - 64 = 26.