Yes, 1 over 12 is a fraction in its lowest terms.
It is: 12/45 = 4/15 as a fraction in its lowest terms
2/3
3/15
It is: 6/12 = 1/2 in its lowest terms
12/33 = 4/11 in its lowest terms
12/48 = 1/4 in its lowest terms
12/17
The fraction 5/12 cannot be reduced any more.
The numbers 5 and 12 are coprime: that is, their only common factor is 1. Therefore, the fraction 5/12 is in its simplest (or lowest) form.
already lowest 7 is a prime number and does not divide evenly in to 12 so answer is still 7/12
10/12 = 5/6 in its lowest terms