Answer:
There is a 99.99998% probability that at least one valve opens.
Step-by-step explanation:
For each valve there are only two possible outcomes. Either it opens on demand, or it does not. This means that 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 combinatios 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:

Calculate P(at least one valve opens).
This is 
Either no valves open, or at least one does. The sum of the probabilities of these events is decimal 1. So:


So


Finally

There is a 99.99998% probability that at least one valve opens.
Answer: 10
Step-by-step explanation:
10% is the same as 10/100
10% would equal 10 (out of the 100) coins
Yes, depending on part of the wind flow maybe. But the Cougars would win atleast 2/3 games
Answer:
The correct answer is 2x - y - 1 = 0
Step-by-step explanation:
To find this, use the ordered pair (1, 1) in any of the equations. If it results in a true statement then this can be an equation.
2x - y - 1 = 0
2(1) - (1) - 1 = 0
2 - 1 - 1 = 0
0 = 0 (TRUE STATEMENT)