If a shopkeeper sells a table at a profit of 12% and a chair at a loss of 18% , he neither gain nor loss on the whole. If he sells the table at 10% profit and a chair at a loss of 8% , he would have gained Rs.210 on the whole. Find the cost price of the table ?

Let table price = T, chair price = C. From first condition: 0.12T - 0.18C = 0, so 12T = 18C, giving C = 2T/3. Substitute in second condition: 0.10T - 0.08C = 210. Using C = 2T/3: 0.10T - 0.08(2T/3) = 210. This gives: 0.10T - 0.16T/3 = 210, or 0.30T/3 - 0.16T/3 = 210, so 0.14T/3 = 210, giving T = 210 × 3/0.14 = 4500. The table costs Rs. 4500.