Answer:
We know that:
Each mechanic can change the oil of 3 cars per hour.
The number of mechanics can change between 0 and a maximum of 4.
Then we can write the variable:
Y = number of oil changes per hour.
Y = 3*X
Where X is the number of mechanics working.
The independent variable is X (number of mechanics), because is the one that Zach can change, and the dependent is Y (number of oil changes) because this depends on the value of X.
Now, the domain will be: {0, 1, 2, 3, 4}
The possible numbers of mechanics working at the same time.
And for the range we must replace those values in our equation, and see the possible values of Y.
Y(0) = 3*0 = 0
Y(1) = 3*1 = 3
Y(2) = 3*2 = 6
Y(3) = 3*3 = 9
Y(4) = 3*4 = 12
Then the range is: {0, 3, 6, 9, 12}
