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.
For number 25 it’s x=4 and for 26 it’s x=7
If the perimeter equals 30 and the length is twice the width, then the length is equal to 20 and the width is equal to 10.
I can't resist helping someone with magic <span>(ノ◕ヮ◕)ノ*:・゚✧
The formula for the volume of a cylinder is pi x r^2 x h.
That's 10240 x pi or 3</span><span>2169.91
</span>(ノ◕ヮ◕)ノ*:・゚✧ woosh you now have smol pener