Answer:
Tickets sold:
VIP 
$17 tickets 
$21 tickets 
Step-by-step explanation:
Let x be the number of VIP tickets.
If ten times as many $17 tickets were sold as VIP tickets, then the number of $17 tickets is
If the number of $17 tickets sold was 57 more than the sum of the number of $21 tickets and VIP tickets, then
and the number y of $21 tickets is 
Amounts earned:
VIP tickets 
$17 tickets 
$21 tickets 
Total 
The sales of all three kinds of tickets would total $51,471, so

Tickets sold:
VIP 
$17 tickets 
$21 tickets 
1 is 117 because 18x6.5 is 117
The triangle is kinda square so multiply and you should get 24
4 *3 = 12
12 * 20 = 240
240 / 2 = 120 units^3
answer is C