Since there are 

 in a circle, and central 

, you can see that the part "sliced out" by the central angle is 

 of the whole circle.
This means that the length of the intercepted arc 

 is 

 of the circumference of the circle. So,
 
 
        
        
        
Answer + Step-by-step explanation:
1) The probability of getting 2 white balls is equal to:

2) the probability of getting 2 white balls is equal to:

3) The probability of getting at least 72 white balls is:

![=\sum^{150}_{k=72} [C^{k}_{150}\times  \left( \frac{8}{15} \right)^{k}  \times \left( \frac{7}{15} \right)^{150-k}]](https://tex.z-dn.net/?f=%3D%5Csum%5E%7B150%7D_%7Bk%3D72%7D%20%5BC%5E%7Bk%7D_%7B150%7D%5Ctimes%20%20%5Cleft%28%20%5Cfrac%7B8%7D%7B15%7D%20%5Cright%29%5E%7Bk%7D%20%20%5Ctimes%20%5Cleft%28%20%5Cfrac%7B7%7D%7B15%7D%20%5Cright%29%5E%7B150-k%7D%5D)
 
        
                    
             
        
        
        
Answer = -20
 -4-5+4+(-5)-4-5+4+(-5) =-20
        
                    
             
        
        
        
Answer:
15.7
Step-by-step explanation:
The equation for finding the circumference of a circle is 
2 x pi x r(radius). Radius is half the diameter.
5/2=2.5
2 x 3.14 x 2.5
=15.7