A furniture company buys back its sold items at ₹2,500 per item (having remaining useful life > 3 years at the time of purchase ).

Mr. Mohan had purchased a table and a sofa set costing ₹4,000 and ₹21,000 respectively, having useful life of 10 years each. After 5 years he returns back these two pieces of furniture. The total estimated annual depreciation on the two furniture pieces is :

₹4,000