At first Money leads Anita by $520. Money gives Anita some money: every $1 he gives drops his lead by $2 (he loses $1, she gains $1). The lead falls from $520 to $100.<br><br>[[model:questions/solutions/q4153.png]]<br><br>• Lead must fall → $520 − $100 = $420<br>• Each $1 given closes the gap by $2 → gift = $420 ÷ 2 = $210<br><br>Money gave Anita $210.<br>Check: Money $1200−$210=$990, Anita $680+$210=$890, lead $990−$890=$100. ✓