Answer:
20 Child tickets
45 Adult tickets
Explanation:
$6/Adult
$3.50/Child
Let A and C stand for the numbers of Adult and Child tickets sold.
A + C = 65
$6*A + $3.5*C = $340
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Rearrange the first equation and use it in the second:
A = 65 - C
6A + 3.5C = 340
6(65 - C) + 3.5C = 340
390 - 6C + 3.5C = 340
-2.5C = -50
C = 20
Use C=20 in the first equation to find A:
A + C = 65
A + 20 = 65
A = 45
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Check to see if these values work:
20*($3.5) + 45*($6) = $340?
$70 + $270 = $340 YES