After M students took a test, the average score was 74%. 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 75%? Choose the correct option:  A) 0.5M + 37  B) M + 0.74  C) 0.75M - 0.5  D) 0.5M + 37.5  E) 37-0.5M
The total number of correct answers for M students is (0.74)*50*M=37*M   For an average of 75%: (total correct answers) / (M+1) = 0.75*50= 
<gadget id="calculator">0.75*50</gadget>
<output>37.5</output>
37.5   Let x be the number of correct answers for the next student.   (x + 37M) / M+1= 37.5   x + 37M= 37.5M+37.5   x = 0.5M + 37.5   The answer is 0.5M + 37.5.
<result>D</result>
After M students took a test, the average score was 74%. 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 75%?