11.3 is rational or irrational ? explain? 0.083 and 2.1371938 to if its not much to ask?

Ignore the - sign for now.   11.3   =   11.3        113
                                                           =
                                                             1             10

Since this is the ratio of two integers, 11.3 is rational.  So is 11.3.

                                                                             83
If you really mean   0.083, this is rational:  it is
                                                                            1000

If y ou meant 0.083333333 ... , that's also rational:  1/12 is equivalent.