可以教我怎么作答吗？

Question

1.Humaira has two dice of different sizes.The difference in volume between the two dice is 37cm³.Given the volume of each dice is a perfect cube.Find the length,in cm,of the sides of both dice.

2.the volume of a cubic water tank is 125 m³.The water in the tank is half filled.One day,37.5m³ of water is poured into the tank.Find the height,in m,of the water in the container now.

3.Siti wants to make a heart-shaped model using 8 pieces of small cubes.Given the volume of the model is less than 6000cm³ and more than 2000cm³.If the length of the cubes is a whole number,find the length,in cm,side of the cube which will be used by Siti.

以上的这3题可以教我做吗？因为我有去找意思但是不懂怎么做。

Comments

9点再回答你好吗

Answer 1

1.

假设x是length of smaller dice，y是length of bigger dice.

所以会得到y³-x³=37,我是慢慢拿号码放进去看能不能找到答案（没办法得情况下；-；）

y是4，x是3. （还好两个号码都不大,要不然这个原始方法真的要不得）

2.

这题如果 cubic water tank应该是指water tank是cube来的，所以全部length都是一样。

因此：³√125 =5m

The water in the tank is half filled。 所以5/2=2.5m

37.5m³ of water is poured into the tank，我们要height，所以37.5/Area of water tank=37.5/（5*5）=1.5m

total height=2.5m+1.5m=4m

3.

这题length好像有两个(好奇为何题目没写find the possible length of cube)

x=length of cube

x³=volume of cube

.Given the volume of the model is less than 6000cm³ and more than 2000cm³

我们form linear inequality， '

2000<8x³<6000

250<x³<750

cube root 全部东西会得到 6.2996<x<9.0856

If the length of the cubes is a whole number

所以x可以是7，8.

如果有错误的话，可以给一下你书本的答案让我看看能不能reverse engineer以下：）