Maths(F.1)
2011-02-08 6:32 am
In a Quiz competition, there are 20 questions.5 marks are awarded for a correct answer and 2 marks are deducted for a wrong answer or no response.If the 'Happy team'scores 51 marks at the end of the competition,how many correct answers does the team get?
回答 (4)
2011-02-08 9:06 pm
✔ 最佳答案
Let a be the number of correct answers the team gets, then the number of wrong answers or no response will be ( 20 – a ) 5a + (-2) . ( 20 – a ) = 515a – 40 + 2a = 517a = 91a = 13 The team gets 13 correct answers.
2011-02-08 7:29 am
let x be correct answer,
5x-2(20-x) = 51
5x-40+2x =51
7x =91
x =13
the team gets 13 correct answer in the competition.
5x-2(20-x) = 51
5x-40+2x =51
7x =91
x =13
the team gets 13 correct answer in the competition.
參考: me
2011-02-08 6:46 am
let y be the no. of 'happy team' answer correctly
5y+(-2)(20-y)=51
5y+(-40+20)=51
7y=91
y=13
So 'happy team' gets 13 correct answers
5y+(-2)(20-y)=51
5y+(-40+20)=51
7y=91
y=13
So 'happy team' gets 13 correct answers
2011-02-08 6:35 am
5x-2(20-x)=51
5x-40+2x=51
x=13
5x-40+2x=51
x=13
收錄日期: 2021-04-19 23:58:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110207000051KK01550