4 boys from Ashok nagar and 6 boys from Balod together can do a piece of work in 5 days, the same work is completed by 5 boys from Ashok nagar and 10 boys from Chandan nagar in 4 days or 3 boys from Balod and 4 boys from Chandan nagar together can do in 10 days. Then how many boys from Ashok nagar can complete the same work in one day?

This is a work problem involving three groups with different rates. Let A, B, C be work rates of boys from Ashok Nagar, Balod, and Chandan Nagar respectively. We have: (4A + 6B) × 5 = 1, (5A + 10C) × 4 = 1, (3B + 4C) × 10 = 1. Solving gives 1/A = 40, so 40 boys from Ashok Nagar can complete the work in 1 day. Options A (20), B (60), and D (80) don't satisfy the equations.