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:
Rs. 144
Step-by-step explanation:
To what the cost of each pen, divide 90/5
You get 18. So each pen costs 18.
Now multiply 18 by 8 and you would get 144.
So, it would cost Rs. 144
First Box
V= L*W*H
V=8*6.25*10.5
V=50*10.5
V=525 inches³
<span>Second Box
</span>V=L*W*H
V=9*5.5*11.75
V=49.5*11.5
V=569.25 inches³
Answer: 40BC and 766AD
Step-by-step explanation:
Area if the rectangle = 42 sq. inch
Area of a rectangle = l × b
42 = 12 × b
b = 42/12 = 3.5 inch
Now, perimeter of a rectangle= 2(l + b)
= 2(12+3.5) = 2(15.5) = 31 inches