The average salary of male employees in a firm was Rs.520 and that of females was Rs.420. The mean salary of all the employees was Rs.500. The percentage of male employees is

Since,x¯1=520,x¯2=420 and x¯=500Also we know x¯=n1x¯1+n2x¯2n1+n2⇒        500n1+n2=520n1+420n2⇒        20n1=80n2⇒        n1:n2=4:1Hence, the percentage of male employees in the firm=44+1×100=80%