The following are the choices on this question:
A.6
B. 39
C. 26
D. 12
The answer is option D. 12.
Check this out:
S=n² + n
S= 12² + 12
(you can get the square of 12 by multiplying 12 by itself: 12 × 12)
S=144 +12
S=156
Complete Question
The complete question is shown on the first uploaded image
Answer:
The probability is 
Step-by-step explanation:
From the question we are told that
The number of cars packed is 
The objective of this solution is to find the probability that the car which has a sunroof also has four doors
This probability is mathematically represented as

Baye's Rule define this probability mathematically as

From the diagram

and 
So

1. Original equation
2.Distributive property
3. Add 6x to each side
4. Subtract 2 from each side
5. Divide each side by 11