From the list of colors: green, red, blue, and white, there are four colors. The concept that should be used in order to determine the number of 4-color code stripes that can be drawn in the sports car is the concept of BASIC PRINCIPLE OF COUNTING.
The equations that would best help us in answering the question is,
n = 4! (that is, four factorial)
For the first pick, there are four choices. When one is already used then, there are only 3 choices for the second color, and so on until the last color.
n = 4 x 3 x 2 x 1 = 24
Thus, there are 24 types of 4-color codes.
I did the box method and my answer was 64x2 x_sqaured minus 16
Answer:

And we can find this probability using the normal standard table or excel and we got:

The figure shows the calculation for this case.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the hardness of a population, and for this case we know the distribution for X is given by:
Where
and 
We are interested on this probability

And the best way to solve this problem is using the normal standard distribution and the z score given by:

If we apply this formula to our probability we got this:

And we can find this probability using the normal standard table or excel and we got:

The figure shows the calculation for this case.
The answer would be 782 because you would round down.
Answer: x=-10, y=13
Step-by-step explanation:

+2y-2y = 0, eliminating y is much easier. So -3x-5x = -8x and 56+24 = 80

Substitute x in any equations but only 1 equation (Don't substitute in both equations.)
For me, I'd substitute x in -3x+2y=50

So the answer is x = -10, y = 13