Question 1148041
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<pre>
Let the number of adults is x.


Then the number of kids is (810-x).


The ratio of kids to adults is


    {{{(810-x)/x}}} = {{{11/7}}}.


It is your basic equation, which you get from the condition.


To solve it, cross multiply; then simplify


    7*(810-x) = 11x

    7*810 - 7x = 11x

    7*810 = 11x + 7x

    7*810 = 18x


    x = {{{(7*810)/18}}} = 315.          <U>ANSWER</U>
</pre>

Solved.