at what rate percent per annum will the simple interest on a sum of money be 1 / 5 of the amount in 10 years ?
"let sum = x . then , s . i . = x / 5 , time = 10 years . rate = ( 100 * x ) / ( x * 5 * 10 ) = 2 % answer : a"
divide(multiply(divide(1, 5), const_100), 10)