Answer:
[tex]\huge\boxed{\sf 25\ ml}[/tex]
Step-by-step explanation:
Total amount of water = 500 ml
Mary drank = 400 ml
Left:
= 500 ml - 400 ml
= 100 ml
This was divided equally among 4 friends.
So,
Each friend got:
= 100 ml/4
= 25 ml
[tex]\rule[225]{225}{2}[/tex]
