Task 355
Task 355: development task in emrekuruu/math-openenv, an RL environment on the Hugging Face Hub. Moving only south and east along the line segments, how many paths are there from $A$ to $B$? asy import olympiad; size(250); defaultpen(linewidth(0.8)); dotfactor=4; for(int i = 0; i <= 9; ++i) if…
The task
Moving only south and east along the line segments, how many paths are there from $A$ to $B$? [asy] import olympiad; size(250); defaultpen(linewidth(0.8)); dotfactor=4; for(int i = 0; i <= 9; ++i) if (i!=4 && i !=5) draw((2i,0)--(2i,3)); for(int j = 0; j <= 3; ++j) draw((0,j)--(18,j)); draw((2*4,0)--(2*4,1)); draw((2*5,0)--(2*5,1)); draw((2*4,2)--(2*4,3)); draw((2*5,2)--(2*5,3)); label("$A$",(0,3),NW); label("$B$",(18,0),E); draw("$N$",(20,1.0)--(20,2.5),3N,EndArrow(4)); draw((19.7,1.3)--(20.3,1.3)); [/asy]