Question

The average of 5 consecutive numbers is n if the next two numbers are also included the average will

• A. increase 1.4
• B. increase by 2
• C. increase by 1
• D. remain the same

Answer 1

The correct option is C increase by 1

$\frac{(x-2)+(x-1)+x+(x+1)+(x+2)}{5}=n$
$\Rightarrow \frac{5x}{5}=n\Rightarrow x=n$
New average
$=\frac{(x-2)+....+(x+2)+(x+3)+(x+4)}{7}$
$=\frac{7n+7}{7}=n+1$