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:
8/27 is represented in decimal as 0.2962962963
The answer is B) <span>(q - 2)(2p - 5r)
</span>2pq - 5qr + 10r - 4p = 2pq - 4p - 5qr + 10r
= 2pq - 4p - (5qr - 10r)
= 2p(q - 2) - 5r(q - 2)
= (q - 2)(2p - 5r)
Answer:
The time you have before finance charges are assessed is called the Grace period
option-D
Step-by-step explanation:
we know that
Grace period is the extra time given to customer to pay amount before finance charges
But once grace period passes , customer will have to pay extra fee or penalty with interest with passing days
So,
The time you have before finance charges are assessed is called the Grace period
So,
option-D