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​

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

1/6

step-by-step explanation:

answer: answer is b.

[m < b = 120º]

step-by-step explanation: