Her pocket money is 6 equal units (sixths). She spent 5 units on lunch, so the 1 unit left is the $3.<br><br>[[model:questions/solutions/q3407.png]]<br><br>• 1 unit (left) → $3<br>• At first → 6 units = 6 × $3 = $18<br><br>She had $18 pocket money.<br>Check: lunch $15 (5 units) + $3 left = $18. ✓