You can change all of these to decimals and then solve or get common denominators.
8.75 + n + 2.375 + 4.5 = 23.125
15.625 + n = 23.125
Subtract 15.625 from both sides
n = 7.5
The answer is C
First you subtract 44,604 from 1,715,760 to get 1,671,156 then you divide 1,671,156 by 27,396 to get 61 people