The cost of construction of a structure is ₹400000. The estimated life of structure is 50 years. At the end of its life period the scrap value is 10% of cost of construction. Considering depreciation at constant rate, what will be the value of the structure after 25 years (excluding scrap value)?
a) ₹300000
b) ₹220000
c) ₹360000
d) ₹180000