Guddi invested some money in a bank at rate of 6% per annum. At simple interest, after 9 years, she got Rs. 8470. How much did she invest?

Rs. 5500

For Simple Interest:

$A = P \left(1 + \frac{RT}{100}\right)$

Where:

• Amount $A = 8470$
• Rate $R = 6\%$
• Time $T = 9\text{ years}$

$8470 = P \left(1 + \frac{6 \times 9}{100}\right)$

$8470 = P(1 + 0.54) = 1.54P$

$P = \frac{8470}{1.54} = 5500$

So, Guddi invested ₹5500.