Answer:
66.76% probability that the levee will NEVER fail in the next 20 years.
Step-by-step explanation:
For each year, there are only two possible outcomes. Either a levee fails during the year, or no levees fail. In each year, the probabilities of levees failing are independent from each other. So we use the binomial probability distribution to solve this problem.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
In this problem we have that:
A levee was designed to protect against floods with an annual exceedance probability of 0.02. This means that 
What is the risk that the levee will NEVER fail in the next 20 years?
This is
when
. So


66.76% probability that the levee will NEVER fail in the next 20 years.
The
second projectile was travelling 1.4 times faster than the first. I
am hoping that this answer has satisfied your query and it will be able to help
you in your endeavor, and if you would like, feel free to ask another question.
Answer:
10: 12 units^2 11: 33 units^2
Step-by-step explanation:
10:
Divide into square and 2 triangles (for simplicity)
square=9
one triangle=3/2
both triangles combined=3
9+3=12
11:
divide into 2 triangles
top triangle: height= 4, base=6
bottom triangle: height= 7, base=6
top=12
bottom=21
Add, 33.
6.4n^2 is correct. math papa helps