Response:
a. 55 cars
b. 25 cars
Detailed explanation:
Let’s denote the quantity of cars with stereo systems as N(ss), those with air conditioning as N(ac), and those with sunroofs as N(sr).
We find that:
N(ss) = 30
N(ac) = 30
N(sr) = 40
N(ss and ac and sr) = 15
N(at least two) = 30
a.
To calculate how many cars possess at least one feature (N(at least one) or N(ss or ac or sr)), we apply:
N(ss or ac or sr) = N(ss) + N(ac) + N(sr) - N(ss and ac) - N(ss and sr) - N(ac and sr) + N(ss and ac and sr)
N(ss or ac or sr) = 30 + 30 + 40 - (N(at least two) + 2*N(ss and ac and sr)) + 15
Substituting, we find N(ss or ac or sr) = 30 + 30 + 40 - (30 + 2*15) + 15 = 55
b.
For those cars that have exactly one feature, we have:
N(only one) = N(at least one) - N(at least two)
N(only one) = 55 - 30 = 25
Refer to the image below. Note that the perimeters are identical since a single rod constitutes the perimeter, and since all rods are of equal length.
The blue line depicted in the attached image illustrates the reflection of f(x) across the x-axis.
To elucidate, the function f(x) is an exponential function displaying the characteristics: the y-intercept calculates as f(0) = 6(0.5)⁰ = 6; the multiplicative rate of change is 0.5, signifying a decay function (decreasing); and the horizontal asymptote exists at y = 0, defining the limit of f(x) as x approaches positive infinity. The reflection across the x-axis for f(x) results in a function denoted as g(x) = -f(x), leading to g(x) reflecting the features discussed including growth into the third quadrant while never intersecting the x-axis. Therefore, using these insights, it is feasible to sketch the corresponding graph across the x-axis.
