27 if the digits can be repeated.
6 if not.
There are 3024 of them.
Ten.
17, 37, 47, 67, 97
45
All of the odd numbers between 11 and 99 inclusive are two digit numbers that are not multiples of 2. There are 45 of them.
There are 60480 numbers.
125
ten factorial = 10! = 3,628,800
5040 numbers can be made.
24 different numbers.
27
6, if you don't repeat any numbers.
24 of them.
60
More than one
48 of them if digits may not be repeated. 100 if they can.
1