5.2.4.41 Various problems on the plane

Condition: In the triangle \( A B C \) on the side \( A B \) the point \( M \) is selected, and on the side \( A C \) the point \( N \) is selected. The segments \( C M \) and \( B N \) intersect at the point \( K \). What is the area of ​​the triangle \( A M N \) if \( B K: K N=9: 4 \), the area of ​​the triangle \( B K C \) is 6/13, and the area of ​​the triangle \( M K N \) is \( 36 / 247 ? \)