请教一个小升初英语奥数题 Three girls A,B and C run in a 100 m race.When A finishes,B is 10 mbehind A and when B finishes C is 20 m behind B.How far in metres was C from A when A finished?(Let’s assume all the athletes run at a constant
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![请教一个小升初英语奥数题 Three girls A,B and C run in a 100 m race.When A finishes,B is 10 mbehind A and when B finishes C is 20 m behind B.How far in metres was C from A when A finished?(Let’s assume all the athletes run at a constant](/uploads/image/z/3172173-69-3.jpg?t=%E8%AF%B7%E6%95%99%E4%B8%80%E4%B8%AA%E5%B0%8F%E5%8D%87%E5%88%9D%E8%8B%B1%E8%AF%AD%E5%A5%A5%E6%95%B0%E9%A2%98+Three+girls+A%2CB+and+C+run+in+a+100+m+race.When+A+finishes%2CB+is+10+mbehind+A+and+when+B+finishes+C+is+20+m+behind+B.How+far+in+metres+was+C+from+A+when+A+finished%3F%28Let%E2%80%99s+assume+all+the+athletes+run+at+a+constant)
请教一个小升初英语奥数题 Three girls A,B and C run in a 100 m race.When A finishes,B is 10 mbehind A and when B finishes C is 20 m behind B.How far in metres was C from A when A finished?(Let’s assume all the athletes run at a constant
请教一个小升初英语奥数题
Three girls A,B and C run in a 100 m race.When A finishes,B is 10 m
behind A and when B finishes C is 20 m behind B.How far in metres was C from A when A finished?(Let’s assume all the athletes run at a constant speed)
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请教一个小升初英语奥数题 Three girls A,B and C run in a 100 m race.When A finishes,B is 10 mbehind A and when B finishes C is 20 m behind B.How far in metres was C from A when A finished?(Let’s assume all the athletes run at a constant
A:B=10:9 B:C=10:8 A:B:C=100:90:72 A:C=100:72 所以当A跑完100M时C跑了72M 所以A比B多跑100-72=28M
三个女孩A,B和C在100米的跑道上比赛。当A完成的时候,B在A后面10米处,当B完成的时候,C在B后面20米处。问:当A完成的时候C与A相距多少米?(假设所有人的速度都一样)
答案是 30m
30m 就是A在B前面10M C在B后面20M 即C在A后面30M
当A到达终点时,时间为T1,C距A的距离为X。A,B,C的速度分别为Va,Vb,Vc
Va T1=100
Vb T1=100-10
Vc T1=100-X
得Vb=9/10 Va
当B到达终点时,时间为T2
Vb T2=100
Vc T2=100-20
得Vb=5/4 Vc
Vb=9/10 Va
Vb=5/4 Vc
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当A到达终点时,时间为T1,C距A的距离为X。A,B,C的速度分别为Va,Vb,Vc
Va T1=100
Vb T1=100-10
Vc T1=100-X
得Vb=9/10 Va
当B到达终点时,时间为T2
Vb T2=100
Vc T2=100-20
得Vb=5/4 Vc
Vb=9/10 Va
Vb=5/4 Vc
得Vc=18/25 Va
Vc T1=100-X
即18/25 Va T1=100-X
即X=100-18/25 *100=28m
即当A到达终点时,C距A的距离为28m
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