After M students took a test, the average score was 56%. If the test has 50 questions, what is the least number of questions that the next student has to get right to bring the average score up to 60%? Answers.
A) M + 30 B) 0.56M + 30 C) M + 28 D) 2M + 28 E) 2M + 30
The total number of correct answers for M students is (0.56)*50*M=28*M   For an average of 75%: (total correct answers) / (M+1) = 0.6*50= 
<gadget id="calculator">0.6*50</gadget>
<output>30</output>
30   Let x be the number of correct answers for the next student.   (x + 28M) / M+1= 30   x + 28M= 30M+30   x = 2M + 30   The answer is 2M + 30.
<result>E</result>
After M students took a test, the average score was 56%. If the test has 50 questions, what is the least number of questions that the next student has to get right to bring the average score up to 60%?