Feb 20, 2020
How many ways are there to walk from $P$ to $Q$ by only taking steps to the right or up?
[asy]
draw((0,0)--(2,0)--(2,6)--(6,6));
draw((0,0)--(0,3)--(6,3)--(6,6));
draw((0,1)--(2,1));
draw((0,2)--(2,2)); <#> draw((1,0)--(1,3)); <#> draw((3,6)--(3,3)); <#> draw((4,6)--(4,3)); <#> draw((5,6)--(5,3)); <#> draw((2,4)--(6,4)); <#> draw((2,5)--(6,5)); <#> label("$P$",(0,0),SW); <#> label("$Q$",(6,6),NE); <#> [/asy]
read more .. 
+28 
+304 
+12 +12 
+16 off-topic
