1. **State the problem:** We know 3 workers take 4 days to build a wall. We want to find how many days 6 workers will take to build the same wall, assuming they work at the same rate. 2. **Formula and concept:** The total work done is constant. Work = Number of workers $ \times $ Number of days. 3. **Calculate total work:** For 3 workers and 4 days, total work = $3 \times 4 = 12$ worker-days. 4. **Find days for 6 workers:** Let the number of days be $d$. Then, $6 \times d = 12$. 5. **Solve for $d$:** $$ d = \frac{12}{6} = 2 $$ 6. **Answer:** It will take 6 workers 2 days to build the wall at the same rate.