Answer:
$80
Explanation:
10 - $5
10 - $10
10 - $20
The drawing will stop when 3 of the same bills are withdrawn. i.e. if any of the bills have been withdrawn for 3 times, the withdrawal will stop.
To maximize the warning, 3 largest bills should be prioritize. In this case $20 bills.
In between the $20 bills, 2 of each bills of the other values should be withdrawn
Hence, 3($20) + 2($10) + 2($5) = 60+20+10 = $80 is the maximum amount