99 because anything less will give you an average of 89 and a decimal
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:
They are not independent
Step-by-step explanation:
Given
E = Occurrence of 1 on first die
F = Sum of the uppermost occurrence in both die is 5
Required
Are E and F independent
First, we need to list the sample space of a roll of a die

Next, we list out the sample space of F


In (1): the sample space of E is:

So:


In (2): the sample space of F is:

So:



For E and F to be independent:

Substitute values for P(E) and P(F)
This gives:


However, the actual value of P(E and F) is 0.
This is so because
and
have 0 common elements:
So:

Compare
and
.
These values are not equal.
Hence: the two events are not independent
Answer:
The correct option is G.Hope this help!!
Dividing fractions is basically the same thing as multiplying but by the reciprocal. I will give an example.
1/2 divided by 1/3
To solve this you do 1/2 multiplied by 3/1 so you switch the numerator and denominator.