homework...(急...)

1)80 toys cars and 64 teddy bears are shared evenly among some childre .
Each child gets the same numbers of toy cars and teddy bears as the other.
what is the maximum number of children..
(80件玩具車同64件玩具熊平均分給一群小孩, 每一個小孩都會分同樣數目的玩具車和玩具熊, 那麼小孩的數目最多為多少?)

H.C.F. of 80 and 64=2x2x2x2=16
so the maximum number of children=16
(80和64的最大公因數=16
所以小孩的數目最多為16人)


2)in a ferry pier,ferries set off for islands A,B and C every 25,45 and 75 minutes
respectively.At 10:00 a.m.,ferries set off from the pier for all the three islands.
when will they set off again if the ferry services end at 11:00 p.m. every day?
List all the possible cases..
(一個碼頭上,渡輪出發往A,B和C島的班次分別是25,45和75一班.10a.m.時,三架渡輪同時出發.如果渡輪服務每天11p.m.結束,那麼三架渡輪何時才會再同時出發?列出所有可能)

L.C.M. of 25,45 and 75=3x3x5x5=225
So for every 225 minutes,i.e. 3 hours and 45 minutes, the ferries will set off again.
Therefore, the ferries will set off again at 1:45 pm,5:30pm and 9:15pm.
(25,45和75的最小公倍數=3x3x5x5=225
所以每225分鐘,即3小時45分鐘,渡輪會再同時出發,可能的時間為1:45 pm,5:30pm and 9:15pm)


3)(分數題)
a bag of panuts weighing two and four over five kg costs $30.Mary buys a bag of peanuts that weighs 4 and two over three kg.How much should she pay...
(一袋豆重2又5分4公斤要30元.Mary買了4又3分2公斤,她要付多少錢?)


1kg of peanut costs=30/(14/5)=$150/14
11/2 kg of peanuts cost=150/14 x 11/2 = $825/14
Mary should pay $825/14
(一公斤豆要=30/(14/5)=$150/14
11/2 公斤要=150/14 x 11/2 = $825/14
所以mary要付$825/14)

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