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.
L = hours used by the Lopez's sprinkler
R = hours used by the Russell's sprinkler
so, we know the Lopez's sprinkler uses 15 Liters per hour, so say after 1 hour it has used 15(1), after 2 hours it has used 15(2), after 3 hours it has used 15(3) liters and after L hours it has used then 15(L) or
15L.
likewise, the Russell's sprinkler, after R hours it has used
40R, since it uses 40 Liters per hour.
we know that both sprinklers combined went on and on for 45 hours, therefore whatever L and R are,
L + R = 45.
we also know that the output on those 45 hours was 1050 Liters, therefore, we know that
15L + 40R = 1050.

how long was the Lopez's on for? well, L = 45 - R.
-2n + 6 is the answer to this question
Answer:
6.5 hours
Step-by-step explanation:
First try to find the rate he can paint per hour
375 ÷ 3 = 125 ft^2 per hour
Then try to find how long it should take it for him to paint 812.5 sq ft
812.5 ÷ 125 = 6.5 hours
is the size in wheels on the scale model .
<u>Step-by-step explanation:</u>
Correct Question : Tom has a scale model of his car. The scale factor is 1 : 12. If the actual car has 16-inch wheels, what size are the wheels on the scale model?
We have , The scale factor is 1 : 12. We need to find If the actual car has 16-inch wheels, what size are the wheels on the scale model .Let's find out:
Ratio of size of wheels to actual size of wheels is 1:12 , but actual car has 16-inch wheels So ,
⇒
{ x is size of wheel in scale model }
⇒ 
⇒ 
⇒ 
Therefore ,
is the size in wheels on the scale model .