They started equal. Sam won 15 and Darren lost 24, so Sam is now 15 + 24 = 39 ahead. Sam now = 4 units, Darren now = 1 unit, so the 3-unit gap is 39.<br><br>[[model:questions/solutions/q4159.png]]<br><br>• Sam ahead now → 15 + 24 = 39<br>• Sam − Darren = 3 units → 39<br>• 1 unit (Darren now) → 39 ÷ 3 = 13<br>• Each at first → Darren now + 24 = 13 + 24 = 37<br><br>Each of them had 37 cards at first.<br>Check: Sam 37+15=52, Darren 37−24=13, and 52 = 4 × 13. ✓