The constant of proportionality is 3.50 since gummy worms are sold at the same rate per pound.
3.50x, equation
3.50(2.5) = $8.75 for 2.5 pounds
81 servings. I found this by making a ratio:
24 c 108 c
------- = -------
18 ser x
I then cross multiplied to get the equation: 24x=1,944. I solved this equation to find x, the number of servings in 108 cups, which was 81.
I remember doing this back in elementary school. I had a hard time with it too!