Find the general term:
4/3, 7/7, 10/11, 13/15,...
note that the next term has a numerator 3 greater than the previous and has denominator 4 greater than the previous. thus, if 4/3 is the first term,
(4 + 3(n-1))/(3 + 4(n-1))
where n = nth term (if 1st, n=1, if 2nd, n=2, etc.)
or simplifying,
(3n + 1)/(4n - 1)
hope this helps~ :)