A 10 foot rope ladder hangs over the side of a boat with the bottom rung on the surface of the water. There is one foot between rungs and the tide goes at the rate of 6 inches per hour. How long until three rungs are covered?
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作者: xudongdong117 时间: 2011-2-19 13:21
Please kindly help give me the answer, I can't think it out, really apriciate your help!作者: yy2235 时间: 2011-2-19 21:26
