Determine a set of 2 numbers that are divisible by the number shown.

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Suppose we want to find how many of the even integers from 2 to 2000 are divisible by m. It is convenient to divide into two cases: (i) m even and (ii) m odd.

(i) If m is even, say m=2n, we want to find the number of integers from 1 to 1000 that are divisible by n. You know how to do that.

(ii) Now let m be odd. Then m divides 2k if and only if m divides k. So we want to find the number of integers between 1 and 1000 that are divisible by m. Again, you know how to do that.

Step-by-step explanation:

Hope this helps :D

expression #3 is not equivalent. the others are.