The average of 10 numbers is X and one of these numbers is 54. If 54 is replaced with 20, then what will be the new average?
Show answer & explanation
Correct answer: B
Explanation
Given:
Average of 10 numbers = X
One number = 54, New number = 20
According to the formula:
Sum = Average × Number
Total Sum = 10X
New Sum = 10X − 54 + 20 = 10X − 34
New Average = (10X − 34)/10
= X − 3.4