Let x = number of adult tickets, and y = number of children tickets. One equation must deal with the number of tickets, and the other equation must deal with the revenue from the tickets.
Then x + y = 300 is the number of tickets
12x + 8y = 3280 is the revenue from the tickets.
Using the substitution method:
x + y = 300   ⇒   y = 300 - x   ⇒   Equation (3)
12x + 8y = 3280   ⇒   12x + 8(300-x) = 3280   ⇒   x = 220
y = 300 - x   ⇒   y = 300-220 ⇒ 80
Therefore 220 adult tickets and 80 children's tickets were sold. 
        
             
        
        
        
Let's attack this problem using the z-score concept.  The sample std. dev. here is (0.25 oz)/sqrt(40), or 0.040.  Thus, the z score representing 3.9 oz. is
        3.9 - 4.0
z = -------------- = -2.5
          0.040 
In one way or another we must find the area under the std. normal curve that lies to the left of z = -2.5.  Use a table of z-scores or a calculator with built-in statistics functions.  According to my TI-83 Plus calculator, that area is
0.006.  One way of interpreting this that with so small a standard deviation, most volumes of coffee put into the jars are very close to the mean, 4 oz.
        
             
        
        
        
It is always a rational number
-Hope This Helps-
        
             
        
        
        
Divide the amount donated by total sales then multiply by 100.
350 / 8750 = 0.04
0.04 x 100 = 4%
 
        
             
        
        
        
Answer: Check
12^10 × 12^(-2) = 12^(10 - 2) = 12^8
________________________________
Second option : ---
3^2 × 4^6 = 3^2 × 4^2 × 4^4 = 12^2 × 4^4
________________________________
Third option : ---
(12^8)^0 = 12^(8 × 0) = 12^0 = 1
________________________________
4th option : Check
12^10 / 12^2 = 12^10 × 12^(-2) = 12^(10 - 2)
= 12^8
________________________________
5th option : Check
2^8 × 6^8 = ( 2 × 6 )^8 = 12^8
Step-by-step explanation: