The average of five numbers is 30. If one number is excluded, the average becomes 31. What is the excluded number?
- A24
- B31
- C26
- D30
Solution & Step-by-step Explanation
Given that the average of 5 numbers is 30:
Sum of 5 numbers=5×30=150
When one number is excluded, the remaining numbers are 4, and their average becomes 31:
Sum of 4 numbers=4×31=124
The excluded number is the difference between the two sums:
Excluded number=Sum of 5 numbers−Sum of 4 numbers
Excluded number=150−124=26
Sum of 5 numbers=5×30=150
When one number is excluded, the remaining numbers are 4, and their average becomes 31:
Sum of 4 numbers=4×31=124
The excluded number is the difference between the two sums:
Excluded number=Sum of 5 numbers−Sum of 4 numbers
Excluded number=150−124=26