German Silver is an alloy of copper, nickel and zinc. It is composed of 60% copper, 20% nickel and 20% zinc. Due to its white-silverish appearance it is named as german silver but it contains no silver in it.
There were 42 students in a hostel. Due to the admission of 13 new students, the expenses of the mess increase by Rs. 30 per day while the average expenditure per head diminished by Rs. 3. What was the original expenditure of the mess ?