Rs 1000 is invested at 10 percent simple interest. Check at the end of every year if the total interest amount is in A.P. If this is an A.P. then find interest amount after 20 years. For this complete the following activity.

₹ 1000 is invested at 10 percent simple interest. Check at the end of every year if the total interest amount is in A.P. If this is an A.P. then find interest amount after 20 years. For this complete the following activity.

Simple interest \(= \frac{P \times R \times N}{100}\). Simple interest after 1 year \(= \frac{1000 \times 10 \times 1}{100} = \square\); after 2 year \(= \frac{1000 \times 10 \times 2}{100} = \square\); after 3 year \(= \frac{\square \times \square \times \square}{100} = 300\). According to this the simple interest for 4, 5, 6 years will be 400, \(\square\), \(\square\) respectively. From this \(d = \square\), and \(a = \square\). \(t_{20} = \square + (20 - 1)\square\); \(t_{20} = \square\). Amount of simple interest after 20 years is = \(\square\)