the population of a town is 7500 . it decreases annually at the rate of 10 % p . a . what was its population 2 years ago ?
"formula : ( after = 100 denominator ago = 100 numerator ) 7500 ã — 100 / 90 ã — 100 / 90 = 9259 a )"
subtract(subtract(7500, multiply(7500, divide(10, const_100))), multiply(subtract(7500, multiply(7500, divide(10, const_100))), divide(10, const_100)))