Answer: Maria has 10 bills of 5€ and 10 bills of 10€.
She has a total of 150€.
Step-by-step explanation:
Let be "f" the number of 5€ bills that Maria has and "t" the number of 10€ bills that Maria has.
Set up a system of equations:
Use the Substitution method to solve the system of equations:
1. Solve for "f" from the first equation:
2. Substitute the equation obtained into the second equation and solve for "t".
Then:
3. Substitute the value of "t" into the equation and evaluate:
Therefore, Maria has 10 bills of 5€ and 10 bills of 10 €.
So the total amount of money she has, is:
She has a total of 150€.