math
posted by Kris .
Of the two fractions 15/21 and 19/17 which is smaller?

estimate 15/21 to 15/20 which reduces to 3/4 of a whole.
Now look at your second fraction, it is an improper fraction and reduces to 1 2/17. Since it is over one whole, and the other fraction is part of a whole, it is larger.