Let us write the rate of compound interest per annum, so that the amount on ₹400 for 2 years becomes ₹441.

Let us write true or false for the following statements

(i) The compound interest will be always less than simple interest for some money at fixed rate of interest for fixed time.

(ii) In case of compound interest, interest is to be added to principal at the fixed time interval. i.e the amount of principal increases continuously.

Let us fill in the blanks:

(i) The compound interest and simple interest for one year at the fixed rate of interest on fixed sum of money are_____________.

(ii) If some things are increased by fixed rate with respect to time, that is ___________.

(iii) If some things are decreased by fixed rate with respect to time this is uniform rate of ___________.

If a sum of money doubles itself at compound interest in n years, let us write in how many years will it become four times.

Let us calculate the principal that at the rate of 5% compound interest per annum becomes ₹615 after two years.