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共回答了11个问题采纳率:90.9% 举报
骑车人追上甲:4/(12-4)=1/2h
乙追上甲:4/(6-4)=2h
联络1:当骑车人第一次追上甲时,甲(或骑车人)与乙相距:(1/2)*12-(1/2)*6=3km
联络2:骑车人与乙相遇需用时:3/(12+6)=1/6h
此时骑车人(乙)与甲相距:4*(1+1/2+1/6)-6(1/2+1/6)=8/3km
联络3:骑车人与甲相遇需用时:(8/3)/(12-4)=1/3h
骑车人再去追乙,此时甲乙相距:4*(1+1/2+1/6+1/3)-6*(1/2+1/6+1/3)=2km
联络4:骑车人与乙相遇需用时:2/(12+6)=1/9h
骑车人需再追甲,此时甲乙相距:4*(1+1/2+1/6+1/3+1/9)-6(1/2+1/6+1/3+1/9)=16/9km
联络5:骑车人与甲相遇需用时:(16/9)/(12-4)=2/9h
骑车人需返回追乙,此时甲乙相距:
4*(1+1/2+1/6+1/3+1/9+2/9)-6*(1/2+1/6+1/3+1/9+2/9)=4/3km
联络6:骑车人与乙相遇需用时:(4/3)/(12+6)=2/27h
此时甲乙相距4*(1+1/2+1/6+1/3+1/9+2/9+2/27)-6*(1/2+1/6+1/3+1/9+2/9+2/27)=32/27km
联络7:骑车人与甲相遇需用时:(32/27)/(12-4)=4/27h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27)=8/9km
联络8:骑车人与乙相遇需用时:(8/9)/(12+6)=4/81h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81)=64/81km
联络9:骑车人与甲相遇需用时:(64/81)/(12-4)=8/81h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81)=16/27km
联络10::骑车人与乙相遇需用时:(16/27)/(12+6)=8/243h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243)=128/243km
联络10::骑车人与甲相遇需用时(128/243)/(12-4)=16/243h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243+16/243)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243+16/243)=32/81km
联络11:::骑车人与乙相遇需用时(32/81)/(12+6)=16/729h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243+16/243+16/729)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243+16/243+16/729)=256/729km
联络12:::骑车人与甲相遇需用时(256/729)/(12-4)=32/729h
此时甲乙相距
4*(1+1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243+16/243+16/729+32/729)-6*(1/2+1/6+1/3+1/9+2/9+2/27+4/27+4/81+8/81+8/243+16/243+16/729+32/729)=192/729km
联络13:::骑车人与乙相遇需用时(192/729)/(12+6)=32/2187h
此时甲乙相距192/729+4*32/2187-6*32/2187=512/2187km
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楼主啊,我实在算不动了,方法就这样了,你再接再厉哈
1年前
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