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:
 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: 2^12
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
125 situps
Step-by-step explanation:
We can use a ratio to solve
25 situp          x situps
---------------  = --------------
12 pushup    60 pushups
Using cross products
25 * 60 = 12x
Divide each side by 12
25*60/12 = 12x/12
125 = x
 
        
             
        
        
        
Answer:
k = 10
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
∠ ZYM is an exterior angle of the triangle, thus
4k + 5 + 6k + 10 = 115, that is
10k + 15 = 115 ( subtract 15 from both sides )
10k = 100 ( divide both sides by 10 )
k = 10