math
posted by Mark .
The sum of my ones and tens digit is 10. My tens digit is greater than my ones digit. I am a prime number. What number am I?

Using your first two sentences, I see only the following possibilities
91
82
73
64
of these only 73 is prime.
I am assuming you wanted only a 2 digit number.
but don't the following also fit all your conditions ?
191,173,1873,1973,3491, .... ?