After MM students took a test, there was a total of 64% of correct answers. If the test contains 50 questions, what is the least number of questions that the next student have to get right to bring the total of correct answers to 70% ? Answers:
A) + 20
B) + 35
C) + 15
D) + 20
E) + 45
Denote xx as the required number of correct answers. xx must satisfy the equation 0.64∗M∗50+x/50M+50=7/10 or 350M+350=320M+10x or x=3M+35   Answer: + 35
<result>B</result>
After MM students took a test, there was a total of 64% of correct answers. If the test contains 50 questions, what is the least number of questions that the next student have to get right to bring the total of correct answers to 70% ?