Use the top-level ratio 5:4 to find how many members and non-members there are, then break each group down using sub-ratios.
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• Top-level ratio 5:4 means 9 units in total.
• 108 ÷ 9 = 12 per unit.
• Members: 5 × 12 = 60
• Non-members: 4 × 12 = 48
For the members (sub-ratio 2 + 3):
• 5 parts = 12 per part
• adults: 2 × 12 = 24
• children: 3 × 12 = 36
For the non-members (sub-ratio 1 + 3):
• 4 parts = 12 per part
• adults: 1 × 12 = 12
• children: 3 × 12 = 36
Total children: 36 + 36 = 72.
Check: 60 + 48 = 108 = total (108). ✓
Final Answer: 72