Well, if you know that $16.50 is the cost for 2... then divide that by 2 to see how much one would cost.
Which would be $8.25
now that you know how much a single ticket costs, then multiply that by the amount of tickets that have to be bought, which would be 5 tickets
so..
$8.25x5
which in total would be
$41.25
Hope this helps!! :)