Answer:
The concentration of the resulting solution is 10%.
Explanation:
Given : Maria has added 4 liters of pure water to 4 liters of a 20% sugar syrup.
To find : What is the concentration of the resulting solution?
Solution :
Maria has 4 liters of a 20% sugar syrup,

New solution is 4+4=8 liters
The concentration of the resulting solution is

Therefore, The concentration of the resulting solution is 10%.