According to BODMAS or DMAS, we first divide, then multiply, next add, and finally subtract. So following the rule we should get 25 because:P = 2Q = 8R = 7S = 55 ( S ) x 7 ( R ) - 2 ( P ) 8 ( Q ) 35 ( 5 x 7 ) - 10 ( 2 8 ) = 25Hence answer should be 25.