Question

The mean of $5$ numbers is $20$. If one number is excluded their mean is $15$. Then the excluded number is

• A. $5$
• B. $40$
• C. $20$
• D. $10$

Answer 1

Answer: (B)

$40$

$\frac{Sum}{Total}=20$

$\frac{Sum}{5}=20$

$Sum=100$

Let no. excluded be $x$

$\frac{NewSum}{Total}=15$

New Sum$=60$

Excluded $N=100-60$

$=40$