The average of five numbers is 30. If one number is excluded, the average becomes 31. What is the excluded number?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 26.
We know that,
Average = Sum of observations/Number of observations
Now,
Sum of five number is = 5 × 30 = 150
When 1 number is excluded then, the sum of 4 numbers is = 31 × 4 = 124
Hence, the excluded number is = 150 -124 = 26