Answer:
If he includes himself then:
Split up the cookies into 4 equal parts.

3.75 cookies each if he includes himself.
If he does not include himself:
Split up the cookies into 3 equal parts

5 cookies each if he shares to his friends without including himself.
Now, check the picture below
the area of the cross-sections, is really the same area as the rectangular faces, so, just use those areas, since they're the same
I don't know what numbers you want me to order from great to least, but a example is 1,510, 964, 478, 219, 96, 57, 35, 10, 9, 4, 3,
All together: <span>3x + 0.05 + x + x + 0.10 = 7.50
5x + 0.15 = 7.50
5x = 7.35
x = 1.47
</span>1.47 +0.10=1.57<span>
so, the drink costs 1.57 </span>