Expanded: 8.000 + .500 + .010 + .007
Word Form: eight ones, five tenths, one hundredth, seven thousandths
Hope this helps!
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.
It’s bevause you can see what you are doing instead of doing it all of your head which could get messed up.
Can u state the problem it is very blurry thx
If he got 5 points in the first round and he needed at least thirty he would score 9 points in the next three rounds