find the compound interest on $ 20000 in 2 years at 4 % per annum , the interest being compounded half - yearly ?
"principle = $ 20000 rate = 2 % half yearly = 4 half years amount = 20000 * ( 1 + 2 / 100 ) ^ 4 = 20000 * 51 / 50 * 51 / 50 * 51 / 50 * 51 / 50 = $ 21648.64 c . i . = 21648.64 - 20000 = $ 1648.64 answer is b"
subtract(multiply(power(add(divide(divide(4, const_100), 2), const_1), 4), 20000), 20000)