Answer:
[tex] \frac{25}{39} [/tex]
Step-by-step explanation:
[tex]\frac 13,~\frac 27,~\frac 3{10},~\frac 4{13},~\frac 5{17}~?[/tex]
Convert them to fractions with their L.C.D (lowest common denominator)
[tex]\frac {15470}{46410},~\frac {13260}{46410},~\frac {13923}{46410},~\frac {14280}{46410},~\frac {13650}{46410}~?[/tex]
hence the two largest are
[tex] \frac{1}{3} \: and \: \frac{4}{13} [/tex]
[tex] \frac{1}{3} + \frac{4}{13} = \frac{25}{39} [/tex]