Answer:
12.8 cm
Step-by-step explanation:
Radius of the can is 8 cm and height is 20 cm.
It is given that after painting his porch Jamil has
of a can of paint remaining. So, first we need to find the total amount of paint in the can.
Total amount of paint in the can is
So, paint in the can ![=\pi r^{2}\times h](https://tex.z-dn.net/?f=%3D%5Cpi%20r%5E%7B2%7D%5Ctimes%20h)
![=\pi (8)^{2}\times 20](https://tex.z-dn.net/?f=%3D%5Cpi%20%288%29%5E%7B2%7D%5Ctimes%2020)
Now
of the can is ![\frac{1}{4}\times \pi (8)^{2}\times 20](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%7D%5Ctimes%20%5Cpi%20%288%29%5E%7B2%7D%5Ctimes%2020)
cubic cm.
Now, let the height of the smaller can be <em>h</em> cm.
Radius of the smaller can is 5 cm.
As, the paint is poured into the smaller can the volume of both the cans will be same.
![\pi (5)^{2}\times h=320\pi](https://tex.z-dn.net/?f=%5Cpi%20%285%29%5E%7B2%7D%5Ctimes%20h%3D320%5Cpi)
![h=\frac{320\pi}{25\pi}](https://tex.z-dn.net/?f=h%3D%5Cfrac%7B320%5Cpi%7D%7B25%5Cpi%7D)
![h=12.8](https://tex.z-dn.net/?f=h%3D12.8)
Hence, height of the smaller can to hold the paint must be 12.8 cm.