What are all two digit co prime number?

Answer 1

Co-prime numbers are those that do not share a greatest common denominator larger than 1.

The list of single digit co-primes is below (note that each co-prime also has a conjunctive, where the terms are reversed)

(1, 1)(1, 2)(1, 3)(1, 4)(1, 5)(1, 6)(1, 7)(1, 8)(1, 9)(2, 1)(2, 3)(2, 5)(2, 7)(2, 9)(3, 1)(3, 2)(3, 4)(3, 5)(3, 7)(3, 8)(4, 1)(4, 3)(4, 5)(4, 7)(4, 9)(5, 1)(5, 2)(5, 3)(5, 4)(5, 6)(5, 7)(5, 8)(5, 9)(6, 1)(6, 5)(6, 7)(7, 1)(7, 2)(7, 3)(7, 4)(7, 5)(7, 6)(7, 8)(7, 9)(8, 1)(8, 3)(8, 5)(8, 7)(8, 9)(9, 1)(9, 2)(9, 4)(9, 5)(9, 7)(9, 8)