To find the number of full trucks we can do 1006 / 12. This gives us 83.8333. That is, 83 full trucks and a bit left over.
The bit left over is the answer to the second part, the last truck. 0.8333 is the same as 10/12, so the last truck will have 10 cars in it. If we didn’t know that fraction, we could find the answer by saying 12x83 = 996. 1006 - 996 = 10.
So the final answer is: 83 full trucks and 10 cars in the last truck.
The cotangent function is defined as the ratio between cosine and sine of a given angle, i.e.

Since you can't have zero at the denominator, the cotangent function is not defined when the sine is zero.
Let's look at your option:
, so the cotangent is defined here
, so the cotangent is not defined here
, so the cotangent is defined here
, so the cotangent is defined here
Answer:
125 minus 81 will give me 34°