The correct answer is Choice B because each of these events are separate items. Each of the others choices will have a part of the additional events that are affected by the first event. When the first event happens in each of these options, the second event's probability is affected by the first outcome. The number of total outcomes changes because of the first event in all choices, except for choice B.
Answer:
1st angle = X
2nd angle = X + 7
3rd angle = X + 18
Then (sum. them): 3X + 25 = 180 ==> X = 51.67 degree
Therefore,
1st angle = 51.67 degree
2nd angle = 58.67 degree
3rd angle = 69.67 degree
