Answer:
girls to boys = 3 : 7
Step-by-step explanation:
girls to boys = 15 : 35
simplify by dividing with 5
girls to boys = 3 : 7
Since point M is the midpoint of AB, then AM=MB.
Consider the area of the triangles ABC and BMC:
where
is the height drawn from the vertex C to the side AB.
So, 
Now

Also

Now consider the area of the triangles AMD and CMD. Let
be the height drawn from the point M to the side AC.

Therefore,

Answer: 