Hey there!!
Let's convert the number of liters to milliliters.
1 liter = 1000 milliliter
30 liters = 1000 × 30 milliliters
= 30,000 milliliters
Bottle - 350 milliliters
Number : 30,000 / 350
= 85.7
Hence, the bottle will need to be used 86 times
Hope my answer helps!