[計量] 數學題目的理解...@@
小弟在做數學的時候，
遇到了這個問題，
On Tuesday, Carla’s Cars sold 2/5 of the cars on the lot,
including 1/3 of the hybrid cars.
If hybrids made up 1/4 of the cars on the lot on Tuesday,
what fraction of the unsold cars were hybrids?
小弟的算法是
2/5 * 1/3 = 2/15
1/4 - 2/15 = 7/60
7/60 / 3/5 = 7/36(Answer)
但是答案卻是5/18
解釋是說1/3 hybrid cards 是1/4的一部份，
所以1/3賣掉了，剩下2/3，
2/3 * 1/4 = 1/6
總共剩下的車輛是3/5，
所以是1/6 / 3/5 = 5/18
但是including不是緊跟在2/5 of the cars on the lot後面嗎?
怎麼變成是去修飾1/4呢...@@
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◆ From: 112.105.143.73
※ 編輯: zero1590 來自: 112.105.143.73 (05/21 00:49)
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