1.某電視機的售價上漲$1200後變成$7600,問電視機售價的百分變化是多少?
2.今年的搶劫案件比去年減少了16%,如果今年的搶劫案件有1512宗,問去年有多少宗?
續百分法(f.3)
2007-09-18 5:36 am
回答 (2)
2007-09-18 6:46 am
1.
Percentage Change
X = 漲價前
Y = 漲價後
X + 1200 = 7600
X * ( 1 + Y%) = 7600
X = 7600 - 1200
X = 6400
Y% = (7600 /X) - 1
Y/ 100 = (7600 / 6400) - 1
Y = 18.75
2.
X = 去年的搶劫案件
Y = 今年的搶劫案件
X * ( 1 - 16%) = 1512
X = 1512 / 84%
X = 1800
Percentage Change
X = 漲價前
Y = 漲價後
X + 1200 = 7600
X * ( 1 + Y%) = 7600
X = 7600 - 1200
X = 6400
Y% = (7600 /X) - 1
Y/ 100 = (7600 / 6400) - 1
Y = 18.75
2.
X = 去年的搶劫案件
Y = 今年的搶劫案件
X * ( 1 - 16%) = 1512
X = 1512 / 84%
X = 1800
參考: Me
2007-09-18 5:42 am
1. Percentage change = 1200/(7600-1200) * 100%
=0.1765*100%
=17.65%(corr to 2 d.p.)
2.No. of crime last year = 1512/(1-16%)
=1800
=0.1765*100%
=17.65%(corr to 2 d.p.)
2.No. of crime last year = 1512/(1-16%)
=1800
參考: Me
收錄日期: 2021-04-13 19:47:57
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070917000051KK03928