10. The interest on Rs. 750 for 2 years is equal to the discount on Rs. 810 for the same time and at the same rate. The rate percent is:

11. The true discount on Rs. 2575 due 4 months hence is Rs. 75. The rate percent is:

12. I want to sell may scooter. There are tow offers, one at cash payment of Rs. 8100 and another at a credit of Rs. 8250 to be paid after 6 months. If money being worth 6 per annum simple interest, which is the better offer: