at what rate percent of simple interest will a sum of money double itself in 11 years ?
"let sum = x . then , s . i . = x . rate = ( 100 * s . i . ) / ( p * t ) = ( 100 * x ) / ( x * 11 ) = 100 / 11 = 9.09 % answer : a"
divide(const_100, 11)