We can divide the list into 4 elements: the first 10 as a, the next 10 as b, the next 10 as c, and the last 10 as d
From the relations we are given, we can form the equations: $\frac{a+b+c}{3}=40,000$
$\frac{b+c+d}{3}=60,000$ and $\frac{a+d}{2}=50,000$
Adding the first two equations, we get $a+2\left(b+c\right)+d=300,000$
We can substitute the value of a+d as 100,000 to get b+c as 100,000
Using this value in the first and second equation would give a and d as 20,000 and 80,000, respectively.
We are told that the average of the first 10 employees increases by 100%, that is, it changes from 20,000 to 40,000
The average of the last 10 increases by 200%; that is, it changes from 80,000 to 240,000
The total of all the four elements would be 40,000+100,000+240.000 = 380,000
Giving the average to be $\frac{380,000}{4}=95,000$
Therefore, Option A is the correct answer.
