11x + 7y + 8 z= (6 x + y + 3z) + (5x + 6y + 5z) From Statement A:6x + y + 3z is multiple of 5 but we cannot say whether 5x + 6y + 5z is a multiple of 5 or not. So Statement A alone is not sufficient.From Statement B:11x + 7y + 8z = (x + 2y + 3z) + (10x + 5y + 5z)We know that x + 2y + 3z is a multiple of 10 and 10x + 5y + 5z is a multiple of 5.So from Statement B we can say that it is divisible by 5.