Answer:
3
Step-by-step explanation:
The total quantity of vinegar needed is ...
(80 mL/student)(30 students) = (80·30) mL = 2400 mL
This is the quantity in ...
(2400 mL)/(1000 mL/bottle) = (2400/1000) bottles = 2.4 bottles
2 bottles is not enough. 3 bottles were needed.