So you know:
1) There are 180° in a triangle.
2) A straight line is also 180°.
So the three angles in the triangle are
2x, 103-x, and (180-(6x-7)).
Solve for x!
2x + 103-x + (180-(6x-7)) = 180
2x + 103-x + 180-6x+7 = 180
-5x = -110
x = 22
90 trucks- for every 2 cars there are 5 trucks
The opposite reciprocal of -1/9 is 9
So the answer is A