Reference answer: $\frac{1}{15}$
74. As shown in the figure, in $\triangle A B C$, $E$ is the intersection of $A D$ and $C F$, $A E=E D$, it is known that the area of triangle $A B C$ is 1, and the area of triangle $B E F$ is $\frac{1}{10}$, then the area of triangle $A E F$ is $\qquad$