the amount of an investment will double in approximately 70 / p years , where p is the percent interest , compounded annually . if thelma invests $ 30,000 in a long - term cd that pays 5 percent interest , compounded annually , what will be the approximate total value of the investment when thelma is ready to retire 42 years later ?
"the amount of an investment will double in approximately 70 / p years , where p is the percent interest , compounded annually . if thelma invests $ 30,000 in a long - term cd that pays 5 percent interest , compounded annually , what will be the approximate total value of the investment when thelma is ready to retire 42 years later ? the investment gets doubled in 70 / p years . therefore , the investment gets doubled in 70 / 5 = every 14 years . after 42 years , the investment will get doubled 42 / 14 = 3 times . so the amount invested will get doubled thrice . so , 30000 * 2 ^ 3 = 240000 hence , the answer is a ."
divide(const_3600, const_10)