If 5 workers can build a wall in 12 days, how long would it take 10 workers (working at the same rate)?

This is an INVERSE proportion — more workers means LESS time. Total work = 5 workers × 12 days = 60 worker-days. With 10 workers: 60 ÷ 10 = 6 days. ASVAB Arithmetic Reasoning tests work-rate problems. KEY INSIGHT: doubling the workers (5 to 10) halves the time (12 to 6 days). Strategy: for inverse relationships, find the total 'work' (workers × time), then divide by the new number of workers. Watch for the inverse relationship — more workers/machines = less time, not more.