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jmc

counting and probability intermediate

Problem

How many integers are between and ?
Solution
We want to count the integers from the first one greater than to the last one less than . We note that for any . Using this expansion for and , we have: We add up, and find the first to be and the second to be . Thus, we want to count the integers between 1062 and 1092, inclusive; there are of these.
Final answer
31