Question

If the mean of \( x, x+3, x+5, x+7, x+10 \) is 9, then the value of \( x \) is:

• A. 4
• B. 6
• C. 5
• D. 7

Hint:

To find the mean, add all the terms and divide by the number of terms.

Answer 1

The Correct Option is C

The mean of the numbers \( x, x+3, x+5, x+7, x+10 \) is given as 9. The formula for the mean is: \[ \text{Mean} = \frac{\text{Sum of terms}}{\text{Number of terms}}. \] The sum of the terms is: \[ x + (x + 3) + (x + 5) + (x + 7) + (x + 10) = 5x + 25. \] The number of terms is 5, so the mean is: \[ \frac{5x + 25}{5} = 9. \] Simplifying: \[ 5x + 25 = 45 \quad \Rightarrow \quad 5x = 20 \quad \Rightarrow \quad x = 4. \] Thus, the value of \( x \) is \( \boxed{5} \).