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Simplify:

$$\frac { 3 }{ 4 } \cdot\frac { 6 }{ 5 } $$

$\cfrac { 9 }{ 11 }$

$\cfrac { 9 }{ 20 }$

$ 3 $

$\cfrac { 9 }{ 10 }$

$\cfrac { 18 }{ 20 }$