The pie chart shows the percentage of employees in 5 branches. Total employees in B1 = 5000. In which of the following sets of branches is the average number of employees 4000?

Solution:

Since B1 = 25% of the total employees and the number of employees in B1 is 5000, the total number of employees is:

\text{Total Employees}=\frac{5000\times 100}{25}=20000

Now calculate the number of employees in each branch.

B2:

20\%\text{of}20000=\frac{20\times 20000}{100}=4000

B3:

15\%\text{of}20000=\frac{15\times 20000}{100}=3000

B4:

30\%\text{of}20000=\frac{30\times 20000}{100}=6000

B5:

10\%\text{of}20000=\frac{10\times 20000}{100}=2000

Now check the average of branches B2, B4 and B5.

\frac{4000+6000+2000}{3}=\frac{12000}{3}=4000

Answer: B2, B4 and B5.