A bill is discounted at 10% per annum. If banker’s discount is allowed, at what rate percent should the proceeds be invested so that nothing will be lost?

Explanation
The bill is discounted at 10% per annum. Banker's discount (BD) is allowed, which means the interest is deducted from the face value of the bill. To avoid any loss, the proceeds should be invested at a rate that earns the same interest as the discount. Mathematically: BD = (BG × 100) / (100 - BG) where BG is the banker's gain. Since the discount rate is 10%: BG = 10 Now, solve for BD: BD = (10 × 100) / (100 - 10) = 1000 / 90 = 100/9 The banker's discount is 100/9, which means the proceeds should be invested at: (100/9) × (1/10) × 100 = 11 1/9%