F.1 math correction
2013-11-08 6:57 am
In a "True/ False" test, there are 25 questions. 4 marks are given for eachcorrect answer, 2 marks are deducted for each wrong answer, and 1 mark is deducted for each question given up. 3 extra marks are given to the student if her / his is more than 50 marks.Peter does not answer all the questions and gets 66 marks in the test. If 9 marks are deducted in total, find the number of the questions that he answers correctly.
回答 (3)
2013-11-08 7:26 am
✔ 最佳答案
Letc be the number of questions that he answers correctly.Marks given for correct answers = 4c
Marks deducted for wrong answers and questions given up = 9
Extra marks = 3
Total marks:
4c - 9 + 3 = 66
4c = 72
c = 18
Ans: Number of questions that he answers correctly = 18
2013-11-08 18:44:25 補充：
Masterijk，知道了，多謝你的提點！
參考: sioieng
2013-11-08 8:11 am
sioieng，很久不見了～
你最近幾好嗎？
台灣化學版那邊最近有陷阱，相信你也知道吧？
唉。。。
你最近幾好嗎？
台灣化學版那邊最近有陷阱，相信你也知道吧？
唉。。。
2013-11-08 7:26 am
Let C be number of correct questions.
W be number of wrong questions.
G be number of given up questions.
4C - 2W - G + 3 = 66
the +3 comes from [3 extra marks are given to thestudent if her / his is more than 50 marks.]
-2W - G = -9
If 9 marks are deducted in total
from 4C - 2W - G + 3 = 66
4C - 2W - G = 63
4C + ( -9) = 63
4C = 72
C = 18
W be number of wrong questions.
G be number of given up questions.
4C - 2W - G + 3 = 66
the +3 comes from [3 extra marks are given to thestudent if her / his is more than 50 marks.]
-2W - G = -9
If 9 marks are deducted in total
from 4C - 2W - G + 3 = 66
4C - 2W - G = 63
4C + ( -9) = 63
4C = 72
C = 18
收錄日期: 2021-04-27 20:34:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20131107000051KK00234