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€.
Answer: C
Step-by-step explanation:
A= 1/2(a+b)xh
A=1/2(7+10)x5
A=8.5x5
A=42.5
The first one is 5
Second 3
Third -7
Fourth is 9
And fifth is 10