Let the cost of one pen, one pencil and one note book be ₹x, ₹ y and ₹ z. From statement I 5x + 6y + 7z = 178 ...(i) From statement II 6x + 4y + 2z = 124 ...(ii) Now if we compare equation (i) & (ii),there is a third statement is require to give the cost of one pen, one pencil and one note book. Therefore both statements are not sufficient to answer the question.