a sum of money at simple interest amounts to rs . 815 in 3 years and to rs . 884 in 4 years . the sum is :
"s . i . for 1 year = rs . ( 884 - 815 ) = rs . 69 . s . i . for 3 years = rs . ( 69 x 3 ) = rs . 207 . principal = rs . ( 815 - 207 ) = rs . 608 . answer : option a"
subtract(815, divide(multiply(subtract(884, 815), 3), 4))