Answer: The answer is: 
d=220, b=300
Step-by-step explanation: 
You could solve this problem using a series of equations:
d+b=520
b-80=d
How I solve this is:
If d+b=520, you could divide 520 by 2 and say that d and b's average is 260 (though that is not their value). 
Then , you know that the difference between them is 80. Since the average is 260, you could add half of 80 (which is 40) and subtract the same to get 220 and 300, which, as you can see, have a difference of 80 and add up to 520. Now you have to find out which is which.
Since 80 fewer tickets were purchased at the door than before the concert (d+80=b (the second equation)), you know that the number of tickets at the door is the lesser number, making the answer:
d=220, b=300
 
        
                    
             
        
        
        
Answer:
The area of the smaller triangle is 75.
Step-by-step explanation:
Here, the ratio of the sides of the similar triangle are 5 : 6
The area if the larger triangle = 108
let us assume that the area of the smaller triangle = m
By the Theorem:
In two similar triangles, the ratio of the areas of similar triangles is the square of the ratio of their sides. 
Similarly, here
 ^2](https://tex.z-dn.net/?f=%5Btex%5D%28%5Cfrac%7B5%7D%7B6%7D%29%20%5E2) = \frac{m}{108}[/tex]
  = \frac{m}{108}[/tex] 
⇒ 
 
or, 
⇒ m = 75
Hence, the area of the smaller triangle is 75.
 
        
             
        
        
        
Answer:
:)
Step-by-step explanation:
5/15 divided by 5 is equal to 1/3 and
 8/12 divided by 2 is 4/6 divided by 2 is 2/3
You have to divide the numerator with the same number that you divide the denominator with.  
 
        
             
        
        
        
The answer is a. <span>It represents a linear function because there is a constant rate of change. This can be done the opposite way, but lets use minutes as x and hours as y. Every time y increases by 1, x increases by 60. This means there is a constant rate of change of 1 (rise) over 60 (run). A linear equation must have a constant rate of change.</span>
        
                    
             
        
        
        
Answer:
The variance for the number of tasters is 4.2
Step-by-step explanation:
For each person, there are only two possible outcomes. Either they are tasters, or they are not. The probability of a person being a taster is independent of any other person. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The variance of the binomial distribution is:

It is known that 70% of the American people are "tasters" with the rest are "non-tasters". Suppose a genetics class of size 20 
This means that 
So

The variance for the number of tasters is 4.2