maths~maths~

2008-08-12 1:35 am

請幫忙！！急！！
1.A cat and a dog are not artisifed with their weights . If the weight of the
cat is increased by 20% while that of the dog is decreased by 10% , their
weights will be the same . What percentage of dog's original weight is cat's
original weight ?

2.Two buckets of the same capacity are filled with flour and suger .The ratio
of flour to sugar in the two buckets are 3:1 and 5:1 respectively . A baker
pours the flour and sugar in the two buckets into one large container . Find
the ratio of flour to sugar in the large container .

3. 3(a+b)+(c-4)(a+b)

need the step!!!thx!!

回答 (1)

Kelvin的SD高達世界

2008-08-12 2:32 am

✔ 最佳答案

1.Let the original weight of the dog be x and the cat be y
since their weights are same,
1.2y=0.9x
so y=0.75x
ie.the originalweight of cat is 75% of the dog

2.let the capacity of two buckets be V
for the first bucket,
the capacity of flour is 3/4V,the capacity of sugar is 1/4V
for the second bucket,
the capacity of flour is 5/6V,the capacity of sugar is 1/6V
so the total capacity of the flour is 19/12V and sugar is 5/12V
hence,the ratio of flour to sugar is (19/12)V/(5/12)V=19:5

3.抽(a+b)出黎
=(a+b)(3+c-4)

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