标题: 请教两道数学题。实在读不懂题... [打印本页] 作者: 今天也要加油鸭 时间: 2018-12-7 10:55 标题: 请教两道数学题。实在读不懂题... 1.Car B starts at point X and moves clockwise around a circular track at a constant rate of 2 mph. Ten hours later, Car A leaves from point X and travels counter-clockwise around the same circular track at a constant rate of 3 mph. If the radius of the track is 10 miles, for how many hours will Car B have been traveling when the cars have passed each other for the first time and put another 12 miles between them (measured around the curve of the track）？
我对MPH这个单位不是很确定。主要我感觉这道题至少要考虑圆的周长吧，毕竟是在圆上跑，但是答案没有...
2.A new tower has just been built at the Verbico military hospital; the number of beds available for patients at the hospital is now 3 times the number available before the new tower was built. Currently, 1/3 of the hospital's original beds, as well as 1/5 of the beds in the new tower, are occupied. For the purposes of renovating the hospital's original wing, all of the patients in the hospital's original beds must be transferred to beds in the new tower. If patients are neither admitted nor discharged during the transfer, what fraction of the beds in the new tower will be unoccupied once the transfer is complete？
这道题真看不懂了... 作者: spicytaco 时间: 2018-12-7 11:14
1.mph=miles per hour =miles/h
2、
假设原来医院中有x张床，那么新建的tower里有2x张床，这样总数就是3x张床（3 times the number available before the new tower was built）
现在原医院中x张床被占了1/3，就是有x/3人，tower里的床被占了1/5，就是有2x/5人，全部搬到tower中的话，tower中有了x/3+2x/5=11x/15人
tower中原本有2x张床，没被占的床的fraction就是(2x-11x/15)/2x=19/30作者: spicytaco 时间: 2018-12-7 11:20
2. 设原来是x
现在就是3x...那么新的bed就是2x
