Re: [計量] 數學
※ 引述《hsingchih (請賜我GRE高分吧!!)》之銘言：
: Worker W produces n units in 5 hours. Workers V and W,working independently
: but at the same time, produce n units in 2 hours. How long would it take
: V alone to produce n units?
: (A) 1hr 26min
: (B) 1hr 53min
: (C) 2hr 30min
: (D) 3hr 20min
: (E) 3hr 30min
: ANS: D
: 謝謝大家幫忙解答~~SORRY~~每次問問題後都忘了謝大家.
令w為W一小時產生product的量
令v為V一小時產生product的量
5w = n -- (1)
w = n / 5 -- (2)
2v + 2w = n -- (3)
將(2)代入(3)得
2v + 2n / 5 = n
2v = n - 2n/5 = 3n / 5
10 / 3 v = n
故V需要3hr 20min才能產生n
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◆ From: 140.138.153.214
※ 編輯: moigai 來自: 140.138.153.214 (10/31 15:24)
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10/31 15:32, 3F
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