For $$a/b > 1$$, when $$a=1, b$$ can not take any value,
$$a=2, b$$ can take $$1$$ value,
$$a=3, b$$ can take $$2$$ value,
$$a=4, b$$ can take $$3$$ values,
$$a=5, b$$ can take $$4$$ values,
$$a=6, b$$ can take $$5$$ values.
Total possible outcomes $$=36$$
$$\therefore P(a/b > 1)=\dfrac{1+2+3+4+5}{36}=\dfrac{15}{36}$$ or $$\dfrac{5}{12}$$