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.
According to his calculations, b has a 3/10 chance to win
Just copy this down. you welcome
Es la segunda media es 1.65, mediana es 1.65, y modo es 1.61
Answer:
B: 22.5 degrees
Step-by-step explanation:
The interior angles of a pentagon add up to 540 degrees
(if you dont believe me you can turn a pentagon into three triangles, 3x180 = 540)
So you have four same angles say measure "x" degrees, and one final one that measures "5x" degrees, so 9x = 540, and x = 60
Unless I read the problem wrong, 60 degrees is the answer which is not an option :P
Edit: Yea I read it wrong, the final angle is 5 times the other four angles COMBINED, so that angle measures "20x" degrees.
The total would be 24x = 540, and so x = 22.5
