If the total cost of constructing the house is Rs. 3,60,000 in 1991 and Rs. 8,64,000 in 2001, what is the amount spent on Steel in 1991 and 2001?

$$\eqalign{ & {\text{Expenditure on steel}} \cr & {\text{Year }}1991 = \frac{{{{50}^ \circ }}}{{{{360}^ \circ }}} \times 360000 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = {\text{Rs. }}50000 \cr & {\text{Year }}2001 = \frac{{864000}}{{360}} \times 60 \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = {\text{Rs. }}144000 \cr} $$