Take Carl’s $6 out of the $16 first. That leaves Alex + Billy = 5 units.<br><br>[[model:questions/solutions/q2299.png]]<br><br>• Alex + Billy → $16 − $6 = $10<br>• 5 units → $10<br>• 1 unit (Billy) → $10 ÷ 5 = $2<br><br>Billy has $2.<br>Check: Billy $2 + Alex $8 + Carl $6 = $16. ✓