a sum of money becomes 7 / 6 of itself in 6 years at a certain rate of simple interest . the rate per annum is ?
"let sum = x . then , amount = 7 x / 6 s . i . = 7 x / 6 - x = x / 6 ; time = 6 years . rate = ( 100 * x ) / ( x * 6 * 6 ) = 25 / 9 % . answer : d"
multiply(divide(subtract(divide(7, 6), const_1), 6), const_100)