What times what equals 2500?

Very many combinations. Using only positive integers, the prime factorization of 2500 is:

2, 2, 5, 5, 5, 5

So these numbers multiplied in any combination gives you a correct answer.

Ex:

2 x 1250

4 x 625

5 x 500

10 x 250

20 x 125

25 x 100

50 x 50

100 x 25

125 x 20

250 x 10

500 x 5

625 x 4

1250 x 2

And of course, 2500 x 1 and 1 x 2500.