Answer:
[tex]Average = \frac{2000(m+f) - (b + 200)m}{f}[/tex]
Step-by-step explanation:
Given
Number of male = m
Number of female = f
Average salary = 2000
Average Salary of male = b + 200
Required
Average salary of female
Average is calculated as follows;
[tex]Average = \frac{Total\ Salary}{Staffs}[/tex]
For the whole company;
The formula becomes
[tex]2000 = \frac{Total\ Salary}{m + f}[/tex]
Multiply both sides by m + f
[tex]2000(m+f) = Total\ Salary[/tex]
The total salary is the sum of the male salary and female salary;
In other words;
Total Salary = Male Salary + Female Salary;
The above expression becomes
[tex]2000(m+f) = Male\ Salary + Female\ Salary[/tex] --------- equation 1
For the male staffs;
[tex]Average = \frac{Male\ Salary}{Male\ Staffs}[/tex]
[tex]b + 200 = \frac{Male\ Salary}{m}[/tex]
Multiply both sides by m
[tex](b+200)m = Male\ Salary[/tex]
Substitute (b + 200)m for Male Salary in equation 1
[tex]2000(m+f) = Male\ Salary + Female\ Salary[/tex]
[tex]2000(m+f) = (b + 200)m + Female\ Salary[/tex]
Subtract both sides by (b + 200)m
[tex]2000(m+f) - (b + 200)m = (b + 200)m -(b + 200)m + Female\ Salary[/tex]
[tex]2000(m+f) - (b + 200)m = Female\ Salary[/tex]
At this point, the average monthly salary of female staffs can be calculated;
[tex]Average = \frac{Female\ Salary}{Female\ Staffs}[/tex]
[tex]Average = \frac{2000(m+f) - (b + 200)m}{f}[/tex]