On selling a table for Rs. 210 and Rs. 420 there will be loss of L1% and L2% respectively. If L1–L2 = 7, then what is the cost price of table

CP of table = Rs. 3000 Let the CP of the Table be 100. With some trial and error you can find that if you sell the table for Rs. 7 and Rs. 14 (notice that one price is twice the other, as given in the question), you will incur losses of 93%(L1) and 86%(L2) respectively. Here L1 - L2 = 7, which satisfies the given condition. Now you can use the unitary method - Rs. 7 corresponds to Rs. 210 Rs. 1 correspond to Rs. 30 Rs. 100 correspond to Rs. 3000 (which is the CP of the Table)

CP =x Since its loss so, L1= (x-210/x ) *100 L2= (x-420/x) *100 L1-L2 = 100*210/x =7 x=3000