maths questions form2

[匿名]

2007-08-09 1:06 am

q.1 pic: http://pichost.xzmo.com/view.php?p=20070808165155.JPG
in the figure , the parallelelograms ABCD and ADMN are similar figures.find BN.

q.2 two buckets of the same capcity are filled with flour and sugar. the ratio flour to sugar in the two buckets are3:1 and5:1 respectively.A baker pours the flour and sugar in the two buckets into one large container. find the tatio of flour to sugar in the large container.

回答 (1)

用戶82723

2007-08-09 1:17 am

✔ 最佳答案

1. For similar figures, the ratio of corresponding sides are the same.
i.e. AB:AD = AD : AN
So (AN + BN) / AD = AD / AN
(5 + BN) / 8 = 8 / 5
5 + BN = 64 / 5
BN = 39 / 5 = 7.8

2. Let x be the capacity of the small buckets.
Then the volumes of flour and suger in bucket A are 3x/4 and x/4 respectively and
those in bucket B are 5x/6 and x/6 respectively.

So, in the larger container, the volumes of flour and sugar are
(3x/4 + 5x/6) and (x/4 + x/6) respectively and hence,

ratio of flour to sugar in the large container
= (3x/4 + 5x/6) : (x/4 + x/6)
= (19/12) : (5/12)
= 19 : 5

參考: My Maths knowledge

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