Question

The average weight of $10$ men is decreased by $3kg$ when one of them whose weight is $80kg$ is replaced by a new person. The weight of the new person is

• A. $70$
• B. $60$
• C. $50$
• D. $73$

Answer 1

Answer: (C)

$50$

Let the mean of $10$ persons =$M$
Sum of weight of the persons $=10M$
After replacing a person weighing 80 Kg with another weighing say$x$ Kg, $sum=10M-80+x$
New Mean$=M-3$
hence,$10(M-3)=10M-80+x$
$10M-30=10M-80+x$
$x=50Kg$