$\frac{8}{6}=\frac{4}{3}=1\frac{1}{3}$ 
Which of these pairs of fractions are equivalent? 

[1] $$3\frac{1}{2}$$ and $$2\frac{1}{4}$$ 
[2] $$1\frac{1}{3}$$ and $$\frac{8}{6}$$ 
[3] $$1\frac{1}{4}$$ and $$\frac{3}{4}$$ 
[4] $$3\frac{3}{9}$$ and $$\frac{9}{9}$$ 