Question

The mean of five numbers is $30$. If one number is excluded, their mean becomes $28$. The excluded number is.

• A. $28$
• B. $30$
• C. $35$
• D. $38$

Answer 1

Answer: (D)

$38$

Let the five numbers be $a,b,c,d,e$

Then, $\frac{a+b+c+d+e}{5}=30$ .... $\left(i\right)$

Let the number excluded be $a$

$\Rightarrow \frac{b+c+d+e}{4}=28$

$⟹b+c+d+e=112$

$⟹a+112=150$ ...... From $\left(i\right)$

$⟹a=38$