求助几道prep输血。。

liuyinghong

1，according to the directions on a can of frozen orange juice concentrate, 1 can of concentrate is to be mixed with 3 cans of water to make orange juice, how many 12-ounce cans of the concentrate are required to prepare 100 6-ounce servings of orange juice?  答案是25
看不懂啊。。。谁能翻译一下。。呜呜

2， If n and y are positive integers and 450y=n的三次方，which of the follwing must be an integer? 答案是第一个，我怎么觉得第一个和第二个都对。。

y/(3×2的平方×5)

y/(3的平方×2×5)

y/(3×2×5的平方)

3， all of the stocks on the over-the-counter market are designated by either a 4-letter or a 5-letter code that is created by using the 26 letters of the alphabet, which of the following gives the maximum number of different stocks that can be designated with these codes?  答案27(26的四次方)
没思路。。


谢谢各位啦。。。

season5924

2，450=3*3*5*5*2，n为整数， y最小=3*5*2*2，所以A must be an integer
3，26的四次方+26的五次方...

liuyinghong

y最小为什么是那个。。。

season5924

我是为了凑出来一个N的三次方...

tingting520

第一题我怎么算出是12.5来着？
12n=100*6*(1/4)
   n=12.5

detectiveyangs

第一题12.5 吧。

根据浓缩橘子汁罐头上的使用说明，做橙汁时1罐浓缩橘子汁兑3罐水，现在需要100份每份6盎司的橙汁，需要多少罐每罐12盎司的浓缩橘子汁？