Irrational numbers cannot be classified as rational numbers. - EXPLANATION - both are different completely, according to as I think, and thus they cannot be inter-related. Irrational like - root2, root3, and all those that cannot be further solved completely. Their decimal representation is neither recurring nor ending e.g. 1.101001000100001000001.... and so on while rational number are consisting of whole numbers, integers, natural numbers, and all the constants and their decimal representation can be non ending but recurring.
5. d. Irrational numbers cannot be classified as rational numbers. - EXPLANATION - out of the options this one's correct. As I above said, all numbers as far as I know can be categorized into unreal and real numbers out of which real numbers consist of irrational and rational numbers while unreal numbers, I don't know as I have not been taught about them yet and neither do you have been, as I think so. All I know is that, as far as I have been taught, unreal number are not connected to real numbers.
6. Every real number is a rational number. - EXPLANATION - As I told you above, real numbers can also be irrational so this is false.
Hope this helps!
