The question asks, "How many integers are there between, but not including, integers r and s?" In other words, the question is asking about all of the integers from r to s, which is another way of saying the number of consecutive integers between the two variables. The prompt does not need to explicitly reference the idea of consecutive integers, because a list of all of the integers within a certain range is the same as a list of the consecutive integers within that range. With that in mind, Statement 1 is sufficient and the answer is (D).
3 Explanations