Question 1118482
Let {{{ S[3] }}} = event that the sum is less than 4 (3 for "3 or less")
Let {{{  D[1] }}} = event that (at least) one die is a 1

P({{{ S[3] }}} |{{{D[1]}}}) * P({{{D[1]}}}) = P({{{D[1]}}} ∩ {{{S[3]}}}) 

  P({{{D[1]}}}) = 11/36
  P({{{D[1]}}} ∩ {{{S[3]}}}) = 3/36

 so
P({{{ S[3] }}}) = (3/36) / (11//36) = {{{ highlight(matrix(1,3, " ", 3/11, " ")) }}}