Can anyone please help me answer this maths question?Two candles have different lengths and different thicknesses.The shorter one would last eleven hours and the longer one would last seven hours.Both candles are lit at the same time,and after three
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Can anyone please help me answer this maths question?Two candles have different lengths and different thicknesses.The shorter one would last eleven hours and the longer one would last seven hours.Both candles are lit at the same time,and after three
Can anyone please help me answer this maths question?
Two candles have different lengths and different thicknesses.The shorter one would last eleven hours and the longer one would last seven hours.Both candles are lit at the same time,and after three hours both have the same length remaining.What was their original lengths?
Can anyone please help me answer this maths question?Two candles have different lengths and different thicknesses.The shorter one would last eleven hours and the longer one would last seven hours.Both candles are lit at the same time,and after three
两根蜡烛长短粗细都不一样.长的可以燃十一个小时,短的可以燃七个小时.如果同时点燃两根蜡烛,三小时后,两根蜡烛长度一样,求两只蜡烛各自的原始长度.
I think we still lack some data if we have to solve this question.I could provide you another similar question with solution to you.
两支粗细不同,长短相同的蜡烛,一支以均匀速度燃烧3小时可以烧完,另一支可以燃烧4小时.现在要求到下午4点钟时,其中一支蜡烛剩余部分的长度是另一支剩余部分的2倍,问应该在下午几点几分同时点燃这两支蜡烛?
细的3个小时烧完,粗的需要4个小时.那么他们燃烧的速度是不一样的,细的烧的快,粗的烧的慢(不理解可以联想现实中的实际情况).但是蜡烛的长度是一个固定的值,可以看做2跟蜡烛长度都为a(或者长度看做是1).则细的蜡烛燃烧速度为a/3,粗的燃烧速度为a/4.设他们同时燃烧并且燃烧了x个小时后,粗的蜡烛长度是细的蜡烛长度的2倍,则根据速度乘以时间等于长度得到
细的蜡烛剩余部分长度为a-a/3*x,粗的剩余为a-a/4*x,建立等式
2(a-a/3*x)=a-a/4*x
可以两边把a约掉得到2(1-x/3)=1-x/4,即2-2x/3=1-x/4,两边同*12并化简得到:12=5x,x=12/5(小时),即2小时又2/5小时,即2小时24分钟
说明从点燃蜡烛那一刻开始,过了2小时24分钟后是下午4点,那么点蜡烛的时间是4点-2点24分=1点36分
即从下午1点36点燃蜡烛开始,过了2个小时24分钟后即下午4点,粗的蜡烛剩余部分是细的蜡烛剩余部分的2倍.
此题关键点:要明白最后是粗的蜡烛是细的蜡烛的2倍、2跟蜡烛的长度是一个固定值可以用任何数据带入(因为蜡烛长度不管取何数值对此题无影响,以后遇到这类情况一般都把这个固定值设为1)、要理解关系式:蜡烛燃烧速度(厘米/小时)*燃烧时间(小时)=燃烧长度(厘米)、有时候解答生活中的实际题目时,在理解时往往需要去联想现实生活.(比如为什么长度相同的2跟蜡烛,粗的烧的比细的慢,联想下实际生活马上会豁然开朗)
以上论述希望有助于你的理解和该问题的解答
两个蜡烛有不同长度和不同厚度。较短的一个将过去十一个小时,久最后七个小时。这两个蜡烛点亮一次,三小时后都具有相同的长度剩余。什么是其原始的长度?