Answer
$\frac{5}{36}$
Work Step by Step
A sum of 6 is 5 of the 36 possible outcomes of two tosses of a die.
$\ \ \ \ \ \ \ 1\ \ \ \ \ \ \ \ \ \ \ \ \ \ 2\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 3\ \ \ \ \ \ \ \ \ \ \ \ \ \ 4\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 5\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 6$
$\ \ \swarrow\downarrow\searrow \ \ \ \ \swarrow\downarrow\searrow\ \ \ \ \ \ \swarrow\downarrow\searrow\ \ \ \ \swarrow\downarrow\searrow\ \ \ \ \ \ \swarrow\downarrow\searrow\ \ \ \ \ \ \swarrow\downarrow\searrow$
$1\ 2\ 3\ 4\ 5\ 6\ \ \ \ \ \ \downarrow\ \ \ \ \ \ \ \ 1\ 2\ 3\ 4\ 5\ 6\ \ \ \ \ \downarrow\ \ \ \ \ \ \ \ 1\ 2\ 3\ 4\ 5\ 6\ \ \ \ \ \ \ \,\downarrow$
$^{2\ \ \ 3\ \ 4\ \ 5\ \ \underline6\ \ 7}\ \ \ \,\ \ \downarrow\ \ \ \ \ \ \ \ ^{4\ \ \ \!\,5\ \,\underline6\ \ 7\ \ 8\ \ 9}\ \ \ \,\ \downarrow\ \ \ \ \ \ \ ^{\underline6\ \ 7\ \ 8\ \ 9\,\,10\,\,11}\ \ \ \ \ \ \downarrow\ \ \ \ \ $
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1\ 2\ 3\ 4\ 5\ 6\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1\ 2\ 3\ 4\ 5\ 6\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1\ 2\ 3\ 4\ 5\ 6$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ^{3\ \ 4\ \ 5\ \ \underline6\ \ 7\ \ 8}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ^{5\,\,\!\underline6\,\,7\ \ 8\ \ 9\ \ 10}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ^{7\ \ 8\ \ 9\ \,10\,11\ 12}\ \ \ \ \ \ \ \ \ $
