Answer:
 the average time spend is 0.111
Step-by-step explanation:
The computation of the average time spend is as follows;
Arrival rate is 
= 210 ÷ 10
= 21 per hour
Now the service rate is 
= 60 ÷ service time 
= 60 ÷ 2 minutes
= 30 per minute
And, finally the average time spend is 
= 1 ÷ (service rate - arrival rate)
= 1 ÷ (30 - 21)
= 0.111
Hence, the average time spend is 0.111
 
        
             
        
        
        
Answer
• A. Equation: 25(5 + x) = 325
,
• B. Answer: 8 dogs
Explanation
Given
• Charge to wash a dog: $25.
• She washed 5 dogs on Saturday and then some more on Sunday.
• She made $325 for the weekend. 
Procedure
She charges $25 per wash, she made $325 for the weekend, and we know that on Saturday she washed 5 dogs, but we don't know how many she washed on Sunday. Thus, we have to build an equation in which the number of dogs washed on Sunday is represented by x (as we do not know the real number).
Considering that the total money made has to be equal to the multiplication of the charge times the dogs washed, the equation is:

Then, we have to solve for x to know how many dogs did she wash on Sunday.
0. Multiplying the parenthesis

<em>2. Subtracting 125 from both sides of the equation</em>


<em>3. Dividing both sides of the equation against 25</em>

 
 
        
             
        
        
        
Giovanni purchased 20 adult tickets and 5 child's tickets.
Step-by-step explanation:
Let,
x = Adult tickets
y = Child's tickets
According to given statement;
x+y=25 Eqn 1
One adult ticket costs $14 and one child ticket costs $8, therefore, 
14x+8y=320 Eqn 2

Putting value of x in Eqn 1;

Giovanni purchased 20 adult tickets and 5 child's tickets.
Keywords: Linear equations, Addition
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