a , b and c have rs . 900 between them , a and c together have rs . 400 and b and c rs . 750 . how much does c have ?
"a + b + c = 900 a + c = 400 b + c = 750 - - - - - - - - - - - - - - a + b + 2 c = 1150 a + b + c = 900 - - - - - - - - - - - - - - - - c = 250 answer : d"
subtract(add(400, 750), 900)