Answer:
a+c=27
195a+320c=6515
Explanation:
adult (a): 195
children (c): 320
total $: $6515
child $: 27
a+c=27 --> c=-a+27
195a+320c=6515
sub the first equation into the 2nd equation to get a=17
sub a=17 into c=-a+27 to get c=10
so, an adult ticket is $17 and a child ticket is $10.