The mean of 10 numbers is 36. When one of the numbers is removed, the mean of the remaining 9 numbers is 34. Which number was removed?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 54
The sum = mean × number of values. The removed number is the difference between the sum of all 10 numbers and the sum of the 9 that remain.
Sum of the 10 numbers \(=10\times36=360\)
Sum of the remaining 9 numbers \(=9\times34=306\)
Number removed \(=360-306=54\)