100/150 = 2/3 a point for each question
12.5
If the test is worth 100 points, each question would be worth approximately 2.86 points.
1 per question.
It depends on the quiz.
16.5% for each error
If you have ordered questions into bullet points then each question (or bullet point) should end with a question mark.
It depends on the test.
Different tests have different rules.
You cannot know that. If you are told the total number of points for the test, you know (or count) the number of questions and you are told that each question is worth the same number of points then, and only then, each question is worth (total points/number of questions) points.
2.381 points each
Generally, in a 10 question quiz, each question carries equal value. However the points given (1,2 or 3...) is determined by the organizer and it may vary in different contests.