The number of people living in a town is 47,000 to the nearest 1,000. Which one of these is a possible number of people living in the town?

If a number is 47,000 to the nearest 1,000, it is within 500 of 47,000.

So it lies from 46,500 up to, but not including, 47,500.

The value 46,500 is included, because 46,500 rounds up to 47,000. The values 46,000 and 48,000 are too far, and 47,500 rounds up to 48,000. So the answer is 46,500.