The mean monthly salary paid to all employees in a certain company was Rs. 600. The mean monthly salaries paid to male and female employees were Rs. 620 and Rs. 520, respectively. Find the percentage of male to female employees in the company.

Let n_{ 1 }= Number of male employees and n_{ 2 } = Number of female employees

Using the formula of combined arithmetic mean, we have

600 = n_{ 1 }(620) + n_{ 2 }(520) /n_{ 1 }+n_{ 2 }

600(n_{ 1 }+n_{ 2 }) = 620$n_{ 1 }$ +520 n_{ 2 }

600$n_{ 1 }$+600$n_{ 2 }$ = 620$n_{ 1 }$ +520 n_{ 2 }

80$n_{ 2 }$ = 20 n_{ 1 }

n_{ 1 }/n_{ 2 } = 80/20=4/1

n_{ 1 } : n_{ 2 } = 4 : 1

Hence, the percentage of male employees =4/5 x 100 = 80 % and the percentage of female employees = 1/5 x 100=20%