Resposta:
[tex]\textsf{Leia abaixo}[/tex]
Explicação passo a passo:
[tex]\mathsf{ A = \{\: \{1,1\} , \{1,3\} , \{3,1\} , \{2,2\} , \{1,5\} , \{5,1\} , \{2,4\} , \{4,2\} , \{3,3\} ...}[/tex][tex]\mathsf{... \{4,4\} , \{5,3\} , \{3,5\} , \{6,2\} , \{2,6\} , \{5,5\} , \{6,4\} , \{4,6\} , \{6,6\} \:\}}[/tex]
[tex]\mathsf{ S = \{\:\{1,1\} , \{1,2\} , \{2,1\} , \{1,3\} , \{3,1\} , \{2,2\} , \{4,1\} , \{1,4\} , \{3,2\} , ...}[/tex]
[tex]\mathsf{...\: \{2,3\} , \{1,5\} , \{5,1\} , \{2,4\} , \{4,2\} , \{3,3\} , \{1,6\} , \{6,1\} , \{4,3\} ,...}[/tex]
[tex]\mathsf{...\: \{3,4\} , \{5,2\} , \{2,5\} , \{4,4\} , \{5,3\} , \{3,5\} , \{6,2\} , \{2,6\} , \{5,4\} ,...}[/tex]
[tex]\mathsf{...\: \{4,5\} , \{6,3\} , \{3,6\} , \{5,5\} , \{6,4\} , \{4,6\} , \{6,5\} , \{5,6\} , \{6,6\} \:\} }[/tex]
[tex]\mathsf{P(A) = \dfrac{n(A)}{n(S)}}[/tex]
[tex]\mathsf{P(A) = \dfrac{18}{36}}[/tex]
[tex]\boxed{\boxed{\mathsf{P(A) = \dfrac{1}{2} = 50\%}}}[/tex]