I can't think of any that are not. Some go out a pretty long ways before they repeat, but they are still rational. I use a rather limiting definition for rational numbers. If you know which digit you are on, you can tell what the next digit will be. For example, If you have a repeating decimal like 0.2334445523344455... and you are told what the 100th digit is, you will be able to claim you know what the 101st digit is. It may not be a simple calculation, but it can be done.
A rectangular prism is a cuboid so volume of cuboid is base area x height which is 5x5x12=300 volume of pyramid is 1/3 x base area x height = 5x5x6x1/3=50 thus volume outside pyramid and inside cuboid is 300-50=250
