Total pieces = 280. Indoor : Outdoor = 9 : 5.<br><br>
[[model:questions/solutions/q10508.png]]<br><br>
Total units = 9 + 5 = 14 units<br>
&bull; 14 units → 280<br>
&bull; 1 unit → 280 ÷ 14 = 20<br>
&bull; Indoor = 9 units = 9 × 20 = 180<br>
&bull; Outdoor = 5 units = 5 × 20 = 100<br><br>
Now find wooden pieces in each group:<br>
Indoor &mdash; wooden : metal = 5 : 4, so wooden indoor = \( \frac{5}{9} \) × 180 = 100<br>
Outdoor &mdash; wooden : metal = 1 : 4, so wooden outdoor = \( \frac{1}{5} \) × 100 = 20<br><br>
Total wooden pieces = 100 + 20 = 120<br>
Check: Metal indoor = 80, metal outdoor = 80. 100 + 20 + 80 + 80 = 280. ✓<br><br>
Final Answer: 120