Question

The average monthly salary of a group of sixteen people is $Rs.500$. If three people of monthly salaries of $Rs.1,000,Rs.1,200$ and $Rs.1,400$ join them and one person of monthly salary of $Rs.800$ leaves them, the new average salary of the group $=Rs.\square$

Answer 1

$\Rightarrow$ The average monthly salary of group of $16$ people is $Rs.500$

$\therefore$ Total monthly salary of $16$ people $=16\times Rs.500=Rs.8000$

When $3$ people salary added then numbers of people $=16+3=19$

$\Rightarrow$ Total salary of $19$ people $=Rs.8000+Rs.1000+Rs.1200+Rs.1400=Rs.11600$

One person of monthly salary of $Rs.800$ leaves then, number of people becomes $=19-1=18$

$\Rightarrow$ Total salary of $18$ people $=Rs.11600-Rs.800=Rs.10800$

$\Rightarrow$ The required average $=\frac{Rs.10800}{18}=Rs.600$