F.3百分法題

1.
x = 1.6y
y = 0.625x

y比x少(1-0.625)x100% = 37.5%

2.
A = 0.7B
A = 1.3C

1.3C = 0.7B
C = (0.7/1.3)B
C = 0.54B (四捨五入）

C是B的(0.54 X 100%) = 54%

2007-12-25 15:05:09 補充：
不好意思，第二題應該如下：2.A = 0.7B1.3A = CA = (1/1.3)C0.7B = (1/1.3)CC = 0.91BC是B的(0.91 X 100%) = 91%

1.40%
2.100%

用百分增減,新-舊over舊x100%

2007-12-25 14:48:11 補充：
絕對唔係1樓果個就咁減=_=但係我唔記得左跟住點做,諗番後補充步驟..

2007-12-25 14:53:02 補充：
我記得啦,第1題160%y=x160%y-100%y over 160%y x100%=37.5%

2007-12-25 14:56:27 補充：
第2題70%b=a130%a=ca=c over 130%70%b=c over 130%91%b=cC=91%B

2007-12-25 14:57:17 補充：
重申一次唔係就咁減答案唔係40%同100%