Question 1201433
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If the probabilities are the same for them to get any of the  3  restaurants at  8  pm,


then the probability that they do really meet is    {{{3*(1/3)*(1/3)}}} = {{{1/3}}}.


The probability that they do not meet at  8 pm is the complement to it,  i.e.    1-{{{1/3}}} = {{{2/3}}}.