Office employees have 30 employess,the average salary of male employees 3 million rupiah a month and the average salary of female employees 2.5 million rupiah a

Office employees have 30 employess,the average salary of male employees 3 million rupiah a month and the average salary of female employees 2.5 million rupiah a month. If the average salary of all office employees is 2.7 million rupiah a month,then the number of male employees is