Answer:
25% percent
Step-by-step explanation:
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.
So if the total is $8.75, and 1 torch costs $7.66, and you bought 1 torch and two batteries, you would have to subtract 8.75 - 7.66 which is 1.09, and then divide that in half to get the price per battery.
Final answer = 1 Battery = $0.54
Answer:
He spend 75.12
Step-by-step explanation:
First determine the amount of the tip
62.60 * 20%
62.60 *.20
12.52
Add this to the cost of the sandwiches
62.60+ 12.52
75.12