Could anybody me with these problems? !

There are 12 boy and13 girls in a class. if the teacher randomly chooses a student’s name out of a hat what is the probability it will be a girl

Find dy/dx using implicit differentiation ln(20+e^xy)=y

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.