Help!I need,Be quick
问题描述:
Help!I need,Be quick
有一个蓄水池及甲乙丙三个放水管,加单独放水12小时可把水池注满,乙单独放水16小时可把水池注满,丙单独排水15小时可把满池水排完,现甲乙两管同时开6小时,关闭乙管,打开丙管,在经过几小时可把水池注满?
答
设经过x小时可把水放满
1-(1/12+1/16)*6=(1/12-1/15)x
1/60*x=1/8
x=7.5
答:再过7.5小时可把水放满.
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