Answer:
The correct answer is option B. 19
Step-by-step explanation:
Fro the figure we can see that,
the number of students across number of answers
To find students correctly answered 30 more questions
From the figure we get,
The number of students answered 30 to 40 questions = 10
The number of students answered 40 to 50 questions = 9
Therefore the students correctly answered 30 more questions = 10 + 9 = 19
The correct answer is option B. 19
