Answer: 80%. Hope this helps, please consider making me Brainliest.
Step-by-step explanation:
To find the percentage, divide the sale cost by the original cost:
27.60/34.50
Let's multiply both sides by 10 to make the operation easier:
27.6/34.5 ( I eliminated the zero's because they kind of have no use) -->
276/345, now solve:
276/345 = 0.8
0.8 = 80%
The percentage is 80%.
 
        
             
        
        
        
The double implication "if and only if" is graphically represented by an arrow pointing in both direction, so the correct writing is

 
        
             
        
        
        
2 largest number is 1/3 and 4/13
1/3 + 4/13 = 25/39
        
             
        
        
        
Answer:Jason is 5 years old.
John is 4 years old.
Jackson is 12 years old.
Step-by-step explanation:
Let x represent the age of Jason.
Let y represent the age of John.
Let z represent the age of Jackson.
The ages of three siblings Jason John and Jackson totals 21 years. It means that 
x + y + z = 21 - - - - - - - - - - -1
Jason is one year older than John. It means that 
x = y + 1
Jackson is three times as old as John. It means that 
z = 3y
Substituting x = y + 1 and z = 3y into equation 1, it becomes
y + 1 + y + 3y = 21
5y = 21 - 1 = 20
y = 20/5 = 4
x = y + 1 = 4 + 1
x = 5
z = 3y = 3 × 4
z = 12
 
        
             
        
        
        
Yes. there is a fixed cost and variable cost.