ECONOMICS (CBSE/UGC NET)

Detailed explanation-1: -To use the rule, divide 72 by the investment return (the interest rate your money will earn). The answer will tell you the number of years it will take to double your money. For example: If your money is in a savings account earning 3% a year, it will take 24 years to double your money (72 / 3 = 24).

Detailed explanation-2: -Answer and Explanation: (a) To solve this problem, we will use the following formula. So, it will take 3.55 years to double the initial investment.

Detailed explanation-3: -r = 5 % . and we are asked to find the time that it would take for money to double if it is invested at this rate if it is compounded annually, that is A=2P A = 2 P . Since this is compound interest, we will be using the formula below. Thus, it will take 14.21 years for the money to double.

Detailed explanation-4: -Let’s say your interest rate is 8%. 72 ∕ 8 = 9, so it will take about 9 years to double your money. A 10% interest rate will double your investment in about 7 years (72 ∕ 10 = 7.2); an amount invested at a 12% interest rate will double in about 6 years (72 ∕ 12 = 6).