Calculate each of the following. State your answers as reduced fractions.
a. 34÷54\displaystyle \frac{{3}}{{4}}\div\frac{{5}}{{4}} =  
b. 54÷15\displaystyle \frac{{5}}{{4}}\div{15} =  
c. 15÷54\displaystyle {15}\div\frac{{5}}{{4}} =  

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