a sum of money at simple interest amounts to rs . 800 in 3 years and to rs . 850 in 4 years . the sum is :
"explanation : s . i . for 1 year = rs . ( 850 - 800 ) = rs . 50 . s . i . for 3 years = rs . ( 50 x 3 ) = rs . 150 . principal = rs . ( 800 - 150 ) = rs . 600 . answer : option c"
subtract(800, divide(multiply(subtract(850, 800), 3), 4))