Answer:
7/20
Step-by-step explanation:
first of all you have to put the two fractions on the same denominators
1/4 (multiply by 5) and you will get 5/20
2/5(multiply by 4) and you will get 8/20
we have to add 5/20 and 8/20 that gives us 13/20
13/20 is the amount he drank
20/20 - 13/20 =7/20
7/20 is the amount of water left that Charlie has left
