maths f1 5 mark
2007-11-08 1:34 am
in a maths competition , participants got 20 marks for a correct answer,lost 10 marks for a wrong answer , or lost 5 marks for each blank answer . if jimmy answered 3 questions correctly, 5 questions wrongly , and left 2 question unanswered , how many marks could he get?點解&點做,列式及答案。
回答 (3)
2007-11-08 1:41 am
✔ 最佳答案
Gain of marks due to correct answers= 3×20
= 60
Loss of marks due to wrong answers
= 5×10
= 50
Loss of marks due to blank answers
= 2×5
= 10
∴Jimmy gets
= 60﹣50﹣10
= 0 mark
2007-11-08 1:44 am
在數學比賽中
答對得 20 分....答錯扣 10 分....空白扣 5 分
所以答對 3 條就得 20*3 = 60 分
答錯 5 條所以扣 10*5 = 50 分
而 2 條無答所以扣 2*5 = 10 分
所以到最後係無分
3*20+ 5*(-10) + 2*(-5)
= 60 +(-50) + (-10)
= 60 - 50 - 10
= 0
答對得 20 分....答錯扣 10 分....空白扣 5 分
所以答對 3 條就得 20*3 = 60 分
答錯 5 條所以扣 10*5 = 50 分
而 2 條無答所以扣 2*5 = 10 分
所以到最後係無分
3*20+ 5*(-10) + 2*(-5)
= 60 +(-50) + (-10)
= 60 - 50 - 10
= 0
2007-11-08 1:43 am
佢有3條岩左,,岩一條又有20分,,咁姐係3x20=60分
跟住佢5條錯左,,錯一條又扣10分,,咁姐係5x (-10)= -50
嘍住佢有2條冇做,,唔做一條又扣5分,,咁姐係2x (-5)= -10
咁最後加曬佢
60+ (-50)+ (-10)
=60 - 50 - 10
=0
一條式過既就係3x20 - 5x10 - 2x5=0
2007-11-07 17:44:47 補充：
打錯字tim係跟住,,唔咪嘍住= ="
跟住佢5條錯左,,錯一條又扣10分,,咁姐係5x (-10)= -50
嘍住佢有2條冇做,,唔做一條又扣5分,,咁姐係2x (-5)= -10
咁最後加曬佢
60+ (-50)+ (-10)
=60 - 50 - 10
=0
一條式過既就係3x20 - 5x10 - 2x5=0
2007-11-07 17:44:47 補充：
打錯字tim係跟住,,唔咪嘍住= ="
參考: mine ah
收錄日期: 2021-04-23 20:44:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071107000051KK02225