A teacher has 51 items to grade, divided into p papers and q quizzes. It takes the teacher 12.4 minutes to grade a paper and 7.75 minutes to grade a quiz. The teacher grades for a total of 465 minutes. Which of the following systems of equations can be used to find the number of quizzes graded? A) 12.4p + 7.75q = 465 p + q = 51
B) 7.75p + 12.4q = 465 p + q = 51
C) 12.4p + 7.75q = 51 p + q = 465
D) 7.75p + 12.4q = 51 p + q = 465​