In a competition,20 marks were given for each correct answer,10 marks were
deducted for each wrong answer,and 5 marks were dudected for each question
given up,Jimmy answered 3 questions correctly,5 questions wrongly,and gave up the rest.If Jimmy got 0 mark at the end,how many questions were provided for
him in the competition?
唔該寫埋算式,點樣解法同埋答案(唔該曬!!!!!!!!)
中一數學功課問題(英文)(急)
2010-10-31 8:43 pm
回答 (2)
2010-11-01 4:08 am
to get the marks for jimmy,let n when he finish all questions
so before the rest,he got
3*20-10*5 =10
if jimmy got 0 mark at the end,he at least when he haven't done
10/5=2 question
or he got wrong ans for
10/10=1 question
at least he finished 9~10 questions
so before the rest,he got
3*20-10*5 =10
if jimmy got 0 mark at the end,he at least when he haven't done
10/5=2 question
or he got wrong ans for
10/10=1 question
at least he finished 9~10 questions
2010-10-31 8:52 pm
3 questions correct:
3 x 20 marks = 60 marks
5 questions wrong:
5 x (-10) marks = (-50) marks
Let X be the number of questions given up,
60 + (-50) + X x (-5) = 0
10 - 5X = 0
X = 2
Therefore, Jimmy had given up 2 questions.
Total number of questions provided
= 3(correct) + 5(wrong) + 2(give up)
=10
Therefore, there were 10 questions provided.
3 x 20 marks = 60 marks
5 questions wrong:
5 x (-10) marks = (-50) marks
Let X be the number of questions given up,
60 + (-50) + X x (-5) = 0
10 - 5X = 0
X = 2
Therefore, Jimmy had given up 2 questions.
Total number of questions provided
= 3(correct) + 5(wrong) + 2(give up)
=10
Therefore, there were 10 questions provided.
收錄日期: 2021-04-23 19:22:44
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https://hk.answers.yahoo.com/question/index?qid=20101031000051KK00446