I am of an age between 10 and 100 I noticed that when I write my age in hexadecimal base 16 the digits are in the reverse order of my age in decimal base 10 how old am I

Are you stating your age as between 10 and 100 (90 years) base 10 (decimal)?

Or are you saying that your age is between 0x10 (16) and 0x100 (64) years which is a 32 year gap?

We have to know what is the number system is being used to generate the range we are looking at.

In base 10, if you let A be the first digit (the tens digits) of your age and B is the units digit your age is written "AB," and the value in base 10 is 10A + B. When written in hexadecimal your age is written "BA," which converted to base 10 has the value 16B +A. So:

10A + B = 16B + A

Rearrange and simplify, and you get:

3A = 5B.

You know that both A and B are integers between 0 and 9 inclusive. There is only one set of values for A and B that satisfies this condition. Can you complete this now?