1.x05ThedistancebetweenAandBis360km/handoneisridingabikefromAatthespeedof20km/h,theotherisridingamotorcyclefromB.Asisknowthatmotorcycle’speedisfourtimesfasterthanbicycleandtheirtravelingdirectionisthesame.Ifthepersonwhoridesabikestarts2hoursearlier,howmuchtimedoesthemotorcycleneedtocatchupwiththebike?
2.x05halfanhourlater.Question:iftheywalkinthesamedirection,howmanyhourswillJohntaketocatchupwithTony?
3.x05ThedistancebetweenAandBis234km.Ittakesoneboat9hoursfromAtoB,iftheboatreturnsfromBtoA,itwilltaketheboat13hours,Question:whatisthespeedoftheboatinstillwaterandthespeedofwater-flowrespectively?
4.x05ThedistancebetweenportAandportBis360km,ittakesaship35hourstocrossandrecrossoncebetweenthetwoports,ittakestheshipincountercurrentdirection5hoursmorethanwhichindownstreamdirection.Weknowthatthespeedofstillwateris12km/h,Question:Howmanyhourswilltheboattakewhenitcrossandrecrossoncebetweenthetwoports?
5.x05Thelengthofatunnelis360m,ifatraingoesintothetunnelfromitsfirstcarriage(车厢)toitslastcarriageandthewholetrainisinthetunnel,thetrainneeds8seconds.Ifitsfirstcarriagegoesintothetunnelandthelastcarriagegoesoutofthetunnel,thetrainneeds20seconds.Question:howlongisthetrain?