a sum of money becomes 7 / 6 of itself in 4 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 = 4 years . rate = ( 100 * x ) / ( x * 6 * 4 ) = 25 / 6 % . answer : a
multiply(divide(subtract(divide(7, 6), const_1), 4), const_100)