The pupils are 9 equal units. Two units failed, so the other 7 units passed = 28.<br><br>[[model:questions/solutions/q3411.png]]<br><br>• Passed = 7 units → 28<br>• 1 unit → 28 ÷ 7 = 4<br>• Failed = 2 units → 2 × 4 = 8<br><br>The number who failed is 8.<br>Check: 8 failed + 28 passed = 36; $$\frac{2}{9}$$ of 36 = 8. ✓