Question

The average of five different positive numbers is 25. x is the decrease in the average when the smallest number among them is replaced by 0. What can be said about x?

• A. x is less than 5
• B. x is greater than 5
• C. x is equal to 5
• D. Nothing can be said

Answer 1

The correct option is A x is less than 5

The change in average will depend on the number replaced. Here we have to replace the smallest number. Since all the numbers are different, the smallest number will have to be lesser than 25, so when we replace the number with zero $\frac{125-24+0}{5}=20.2$
Change in average is 25 – 20.2 = 4.8
Similarly, change in average will always be less than 5. For the change to be greater than 5, the number being replaced should be greater than 25, which is not possible as we have to replace the smallest number.