Question 1063124
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The number of adults tickets sold, a, was eight times the number of child tickets sold, c,. 
Child tickets cost $2.50 each; adult tickets cost $5.00 each and last night's show brought in $850.
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You can solve the problem mentally,  without using equations.


<U>HINT</U>: You can group the tickets in sets in a way each set contains &nbsp;8&nbsp; adult tickets and &nbsp;1&nbsp; child ticket.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Then each set is worth &nbsp;8*5 + 2.50 dollars = 42.50 dollars, &nbsp;and the number of sets is &nbsp;{{{850/42.50}}} = 20.


Did you get the idea ?