Answer:
D: $26.25 I just took the assessment and got it right
The answer is n=24 because 7x3=21 8x3=24
B or D choose one of them that what I think!!
The two given angles are vertical angles and equal each other:
3x + 50 = 6x -10
Now solve for x:
Subtract 3x from both sides:
50 = 3x -10
Add 10 to both sides:
60 = 3x
Divide both sides by 3
X = 20
Observe the given figure.
Here, angle T and R are the inscribed angles.
And sum of inscribed angles is half of measure of intercepted arcs.
Since, the measure of intercepted arcs is 360 degrees.
Therefore, 

Hence, the sum of the two angles is 180 degrees.
Therefore, these are the supplementary angles.
Therefore, angle T and angle R are supplementary angles.
Hence, proved.