Which of the following fraction is the largest?

Here to say which fraction is greater from the given options, the fraction with greater numerator with same denominator or smaller denominator with same numerator.

To find the greater fraction, among the given options, make the denominators same for the options by finding the LCM of all the denominators.

7/12, 9/16, 13/20, 32/80

Now, LCM of 12, 16, 20, 80 = 240.

Then,

140/240, 135/240, 156/240, 96/240

Here 

$\frac{156}{240} > \frac{140}{240} > \frac{135}{240} > \frac{96}{240}=> \frac{13}{20} > \frac{7}{12} > \frac{9}{16} > \frac{32}{80}$

Hence, largest fraction = 13/20.