Question 1130094
<pre>
                QUANTITY      SALES-MONEY
children         2y            5*2y
students        315-3y         7(315-3y)
adults            y           12y
TOTAL            315          2282
</pre>

The sum of the revenues of each group is  2282 dollars.

{{{10y+7*315-21y+12y=2282}}}
-
{{{y=2282-7*315}}}

{{{highlight(y=77)}}}--------use this to find the other two quantities.