SOMETHING FOR PROFIT
A friend of mine bought a used pressure cooker for Rs. 60. She somehow did not find it useful and so when a • friend of hers offered her Rs. 70 she sold it to her. However, she felt bad after selling it and decided to buy it back from her friend' by offering her Rs. After having bought it ooce again she felt that she did not really need the cooker. So she sold it at the auction for Rs. 90.
How much profit did she make? Did she at all make any profit?