RRB NTPC CBT I 30 Dec 2020 Shift 2 Paper

The average salary of the entire staff in an office is Rs. 3,560 per month. The average salary of the officers is Rs. 5,400 per month and that of the non-officers is Rs. 2,600 per month. If the number of officers is 12, find the number of non-officers in the office.