敬请高手帮我做道选择题,谢谢You are trying to fill a bath with both taps on,but have accidentally left out the plug.Normally the hot water tap takes 8 minutes to fill the bath and the cold water tap takes 10 minutes.However,the water empties out through the plug hole in 5 minutes.How long will it take for the bath to fill?A 10 minutes B 20 minutes C 30 minutes D 40 minutes
热心网友
应该是D.设需要x分钟。（1/8+1/10-1/5）x=1(5/40+4/40-8/40）x=11/40x=1x=1*40/1x=40
热心网友
D.40 minutes 1/(1/8+1/10-1/5)=40很明显的数学题.小学生都能算的,译为汉语后很清楚的.热水管8分钟注满,冷水管10分钟注满.同时加水(with two taps on),下水管放水5分钟.问几分钟能注满?
热心网友
数学题，给浴缸放水，冷热水同时放，但忘了堵上下水道。所以放出的水一直在往外流。已知热水管放满整缸水需要8分钟，冷水管放满整缸水需要10分钟。而整缸水只需5分钟就会从下水道流个干干净净。问将浴缸放满需要多长时间？我的数学不够好。 555。做不出来。