Question 798490
<pre>
Let the three people be Tom, Dick, and Harry.

The probability that Tom will get off on one of the floors is 1, since
it is certain that he will.

The probability that Dick will get off on the same floor that Tom
got off on is 1/6.

The probability that Harry will then get off on the same floor that Tom
and Dick got off on is 1/6.

Answer: 1×{{{1/6}}}×{{{1/6}}} = {{{1/36}}} = 0.027777... round to 0.278

Edwin</pre>