You are taking a test in which multiple choice questions are worth 9 points and fill in questions are worth 14 points. It takes 3 minutes for each multiple choice question and 5 minutes for each fill in question. The total time allowed is 60 minutes and you do exactly 12 questions. your score is 168 points by using the entire 60 minutes. Find how many questions of each type you answered correctly.
How many multiple choice questions did you answer correctly?_____________
How many fill in questions did you answer correctly?______________
2007-05-16 22:12:19 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Let no of MCQ= x
Let no of Fill in Q= y
x + y = 12 -------------------- (1)
9x + 14y = 168 ------------- (2)
From 1,
x= 12-y ------------------------ (3)
Sub (3) into (2)
9(12-y) + 14y = 168
108 - 9y + 14y = 168
5y = 60
y= 12
x=0
No of MCQ= 0
No of fill in questions = 12
2007-05-16 22:19:07 · answer #1 · answered by febbfish 2 · 0⤊ 0⤋
Ok lets start simple. You have a total of 168.
60/3 = 20 max 3 min questions
60/5 = 12 max 5 min questions
20 x 9 = 180 if all 3 min questions
12 x 14 = 168 if all 5 min questions
Before we go any further we alrady have the answer.
multiple choice correct 0
fill in correct 12
2007-05-17 05:19:50 · answer #2 · answered by Brian 5 · 0⤊ 0⤋
12 fill in were answered correctly, no multiple choice.
2007-05-17 05:21:07 · answer #3 · answered by ckenjoos@sbcglobal.net 2 · 0⤊ 0⤋