推 PINKENVI:非常感謝.... 06/14 16:26
※ 引述《PINKENVI (非要考好不可!)》之銘言：
: Q9:
: How many years did Dr. Jones live?
: (1) If Dr. Jones had become a doctor 10 years earlier than he did,
: he would have been a doctor for exactly 2/3 of his life.
: (2) If Dr. Jones had become a doctor 10 years later than he did,
: he would have been a doctor for exactly 1/3 of his life.
: ANS: C
: 可以請教此題列式嗎...
: 我知道答案是c，可是我不太清楚如何列式。腦筋有點轉不過來...@@
: 請指點迷津，thanks a lot...
可把總年齡設為X ，當醫生的年紀設為Y
第一個條件可得 『X-(Y-10)』=2/3X
第二個條件可得 『X-(Y+10)』=1/3X
兩方程式解聯立
就OK摟
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