Jack says, "There is no rational number between 1 7 and 1 8 ." Mary replies, "Yes there is, because 2 15 is between them." Is Mary right? A) No, because the denominators are different. B) No, since there 2 is larger than 1 and 15 is larger than 7 or 8. C) Yes, because 1 7 + 1 8 = 2 15 , which is between them. D) Yes, since 1 7 = 0.143, 1 8 = 0.125, and 2 15 = 0.133.