Answer:
The probability that 8 mice are required is 0.2428.
Step-by-step explanation:
Given : A scientist inoculates mice, one at a time, with a disease germ until he finds 3 that have contracted the disease. If the probability of contracting the disease is two sevenths.
To find : What is the probability that 8 mice are required? The probability that that 8 mice are required is nothing ?
Solution :
Applying binomial distribution,

Where, p is the probability of success 
q is the probability of failure q=1-p, 
n is total number of trials n=8
r=3
Substitute the values,




Therefore, the probability that 8 mice are required is 0.2428.
Answer:
390 miles
Step-by-step explanation:
Using a graphical tool we obtain that the solution of this system
(intersection between the lines)
is given by the point
(x,y) = (2,4)
Answer:
17. 15
18. 8(this one I'm not sure tho what does the right one say)
19. 32
20. 5