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:
No, because there is just as high of a possibility that the other is biased too.
3x27=81 so 81 is a multiple of 3
there is no integer x for which 4x=46 so 46 is not a multiple of 4
there is no integer x for which 7x=55 so 55 is not a multiple of 7
72 = 8*9 so 72 is a multiple of 9
there is no integer x for which 6x=45 hence 45 is not a multiple of 6
After you've calculated a least common multiple, always check to be sure your answer can be divided evenly by both numbers. Find the LCM of these sets of numbers. Multiply each factor the greatest number of times it occurs in any of the numbers. 9 has two 3's, and 21 has one 7, so we multiply 3 two times, and 7 once.
Answer:
1. y= 3x+7
2.y=1/2 x -1
Step-by-step explanation:
1.
Parallel lines have the same gradient.In the equation given,
y= 3x+5 , the slope is 3
So now, you find the equation of a line passing through point (-1,4) with m=3
m=Δ y/Δx
3= y-4/ x--1
3= y-4 /x+1
3(x+1) = y-4
3x+3 =y-4
3x+3+4=y
⇒⇒ y= 3x+7 is the equation.
2.
Two lines that are perpendicular to each other have the product of their slopes to be -1
Given equation to be y= -2x +8 then, m₁ = -2
Finding m₂ will be;
m₁ *m₂ = -1
-2 * m₂ = -1
-2 m₂ = -1
m₂ = -1/-2 = 1/2
So writing the equation of the perpendicular line with m₂ =1/2 , point (-4,-3)
will be;
m=Δy/Δx
1/2=y--3/x--4
1/2 = y+3/x+4
x+4 = 2( y+3)
x+4 = 2(y+3)
x+4 =2y+6
x+4-6=2y
x-2=2y
x/2 -2/2=y
y=1/2 x -1 is the equation.