1. 16/4; just divide the denominator, 4, by 4 to get 1; divided the numerator 16 by 4, too, and you will get 4/1
2. 165/5; do the same as question 1. divide the denominator, 5, by 5 to get one, and divided the numerator, 165, by 5, too, and you will get 33/1
remember: whatever you do to the top (numerator), do to the bottom (denominator)
hope this helps