小明测驗有30題..答對有3分 答錯扣一分
小明做哂全部 小明最小有60分
咁佢最多答錯幾多題?? 答案 : 7題
設小明最多答錯了 x 題..
我只係要條式~~~唔該...幫幫手~~
數學題....我只係要式(10)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2008-12-12 2:54 am
回答 (6)
2008-12-24 9:12 pm
小明测驗有30題..答對有3分 答錯扣一分
小明做哂全部 小明最小有60分
咁佢最多答錯幾多題?? 答案 : 7題
設小明最多答錯了 x 題..
我只係要條式~~~唔該...幫幫手~~
可以:
(30x3-60)÷(3+1)
=30÷4
=7 1/2
~7
小明做哂全部 小明最小有60分
咁佢最多答錯幾多題?? 答案 : 7題
設小明最多答錯了 x 題..
我只係要條式~~~唔該...幫幫手~~
可以:
(30x3-60)÷(3+1)
=30÷4
=7 1/2
~7
2008-12-13 8:46 pm
設小明最多答錯了x題。
3(30-x)+x(-1)>60
90-3x-x>60
90-4x>60
90>60+4x
90-60>4x
30>4x
7.5>x
x<7.5
∴小明最多答錯了7題。
3(30-x)+x(-1)>60
90-3x-x>60
90-4x>60
90>60+4x
90-60>4x
30>4x
7.5>x
x<7.5
∴小明最多答錯了7題。
2008-12-12 3:38 am
The answer is:
60-7x
60-7x
2008-12-12 3:12 am
Number of questions that is correct = 30 - x.
Marks received = 3(30 - x).
Marks deducted due to wrong answers = -x.
so 3(30 - x) - x > 60.
90 - 3x - x > 60
30 > 4x
7.5 > x
so greatest value of x = 7.
Marks received = 3(30 - x).
Marks deducted due to wrong answers = -x.
so 3(30 - x) - x > 60.
90 - 3x - x > 60
30 > 4x
7.5 > x
so greatest value of x = 7.
參考: me
2008-12-12 3:08 am
設小明最多答錯了 x 題
(30-x) *3 + x(-1) >60
(30-x) *3 + x(-1) >60
2008-12-12 3:04 am
Number of questions that is correct = 30 - x.
Marks received = 3(30 - x).
Marks deducted due to wrong answers = -x.
so 3(30 - x) - x > 60.
90 - 3x - x > 60
30 > 4x
7.5 > x
so greatest value of x = 7.
Marks received = 3(30 - x).
Marks deducted due to wrong answers = -x.
so 3(30 - x) - x > 60.
90 - 3x - x > 60
30 > 4x
7.5 > x
so greatest value of x = 7.
收錄日期: 2021-04-25 22:38:37
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081211000051KK01202