The average number of male employees in offices A, D and F is what per cent more
than the total number of female employees in offices B, E and F?

Number of male employees in E = $$\frac{50.4}{360}\times\ Total\ Male$$ i.e. 224.
This gives the number of Total male employees = 1600.
And Total employees in C = $$\frac{43.2}{360}\times\ Total$$ i.e. 288.
This gives the Total number of Employees = 2400.
Using these values, we can calculate Total number of Employees and Total number of Female employees for all the offices.

average number of male employees in offices A, D and F = 336 and the total number of female employees in offices B, E and F are 280.
The required percentage = $$\frac{336-280}{280}\times\ 100\ =\ 20\%$$.