Adding a negative number is the same as subtracting a positive number. So 2315.5 - 3166.75 = -851.25
25% of people leave early as 6 is 1/4 of 24. You can solve this by dividing 6 by 24 (I believe, maybe check with someone on that but that’s how i figured it out).
8/5 divided by 3 in fraction form is 8/15
