a sum of money at simple interest amounts to rs . 825 in 3 years and to rs . 840 in 4 years . the sum is ?
"s . i . for 1 year = ( 841 - 825 ) = rs . 16 s . i . for 3 years = 16 * 3 = rs . 48 principal = ( 825 - 48 ) = rs . 777 . answer : c"
subtract(825, divide(multiply(subtract(840, 825), 3), 4))