2000X4+(9-4)X500= 10500

Option 2: Make part of it into milk slices and the rest into yogurt for sale, which will be completed in exactly 4 days.

I used milk tablets for one and a half days and yogurt for two and a half days. It only took four days.

2.5x3x 1200+ 1.5x 1x 2000 = 1 1000

Option 2 is more profitable.