→ dxzil:筆誤:P 應該是P：Ave - 1 revolution/ 6"s" <---秒 08/20 08:29
→ dxzil:筆誤:P 應該是Q：Ave - 1 revolution/ 1.5"s" <---秒 08/20 08:30
推 Diablotin:謝謝你！ 08/20 11:41
※ 引述《Diablotin (咕嚕咕嚕)》之銘言：
: 51. 6587-!-item-!-187;#058&005111
: Circular gears P and Q start rotating at the same time at constant speeds.
: Gear P makes 10 revolutions per minute, and gear Q makes 40 revolutions
: per minute. How many seconds after the gears start rotating will gear Q
: have made exactly 6 more revolutions than gear P ?
: (A) 6
: (B) 8
: (C) 10
: (D) 12
: (E) 15
P：Ave - 1 revolution/ 6 mins
Q：Ave - 1 revolution/1.5 mins
試問需多少時間，Q的revolutions會比P多6圈？
那就來假設吧~
Let x = 所需時間 x/1.5 - x/6 = 6
解出 x = 12 :)
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