Each fraction is being increased by [tex] \frac{3}{20} [/tex]
[tex] \frac{3}{20}[/tex] , [tex] \frac{6}{20} [/tex] , [tex] \frac{9}{20} [/tex] , [tex] \frac{12}{20} [/tex] , [tex] \frac{15}{20} [/tex]
The next fraction in this sequence would be [tex] \frac{15}{20} [/tex]