Question 1165074
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Group all the tickets sold into groups of 3 adult tickets and one child ticket.  The cost of each such group of tickets is 3($8.90)+$5.30 = $26.70+$5.30 = $32.<br>
The number of those groups of tickets that need to be sold to make $800 is 800/32 = 25.<br>
Then, since each group consists of 3 adult tickets and one child ticket, the number of child tickets sold was 25.<br>
For a formal algebraic setup....<br>
x = # of child tickets at $5.30 each
3x = # of adult tickets at $8.90 each<br>
Total sales were $800:<br>
{{{5.30(x)+8.90(3x)= 800}}}<br>
Solve using basic algebra....<br>