Exercise 2 - solution

Changes:
for d_mm in (1.0, 0.5, 0.25, 0.125):
    ...
for ratio in (15, 18):
    print(f"25 g coffee at {ratio}:1 -> {25 * ratio} g water")

Results:
particle 0.125 mm -> surface/volume 48 per mm
25 g coffee at 15:1 -> 375 g water
25 g coffee at 18:1 -> 450 g water

48 / 6 = 8, so the 0.125 mm particle has 8 times the surface per unit volume of the 1.0 mm one (illustration only, spherical particles, invented sizes).