The price of gasoline increases by 20%.What should be the percentage change in the consumption of gasoline so that the expenditure remains unchanged?
希望可以有埋解釋,因為我唔系好明點計
中三英數一條
2009-10-17 3:36 am
回答 (2)
2009-10-17 3:55 am
✔ 最佳答案
Let the original price per $X per unit volume
Let the orginal consumption be Y
Original cost = $XY
New price per unit volume = $X * ( 1+ 20%) = $1.2X
New consumption = total cost / price
= $XY / $1.2X
= Y/1.2
Percentage of decrease in consumption = (Y - Y/1.2) / Y * 100%
= 16.67%
2009-10-21 3:23 am
收錄日期: 2021-04-23 23:19:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091016000051KK01128