Question 943371
A theater has 48 seats arranged in 8 rows of 6 seats each. three friends buy
tickets separately. what is probability they will end up in same row?
<pre>
Only the number of rows matters. [The 48 and 6 are irrelevant.]

Suppose the friends are A, B and C.

{{{P(matrix(1,5,  

(matrix(7,1,A, will, be, assigned, to, some, row))^"",

AND,

(matrix(8,1,B, will, be, assigned, to, that, same, row))^"",

AND,

(matrix(8,1,C, will, be, assigned, to, that, same, row))^""

))}}} {{{""=""}}}
   [Since "AND" tells us to multiply probabilities] 
{{{P(matrix(7,1,A, will, be, assigned, to, some, row))*

P(matrix(8,1,B, will, be, assigned, to, that, same, row))*

P(matrix(8,1,C, will, be, assigned, to, that, same, row)) }}} {{{""=""}}}

{{{(1)*(1/8)*(1/8)}}} {{{""=""}}} {{{1/64}}}

[Notice that the first probability is 1 because it is certain
that A will be assigned to some row.]

Edwin</pre>