3/10
Explanation:Amount of icecream they ate = 3/4
Fraction of fudge bars = 2/5
Fraction of the available ice cream was fudge bars = 2/5 of 3/4
[tex]\begin{gathered} of\text{ means multiplication} \\ \frac{2}{5}\times\frac{3}{4} \end{gathered}[/tex][tex]\begin{gathered} =\frac{6}{20} \\ =\frac{3}{10} \end{gathered}[/tex]Fraction of the available ice cream that was fudge bars = 3/10