the present population of a town is 500 . population increase rate is 10 % p . a . find the population of town before 2 years ?
"p = 500 r = 10 % required population of town = p / ( 1 + r / 100 ) ^ t = 500 / ( 1 + 10 / 100 ) ^ 2 = 500 / ( 11 / 10 ) ^ 2 = 413 ( approximately ) answer is d"
add(500, divide(multiply(500, 10), const_100))