1. The problem states that you work for 4 days and then rest for 3 days, repeating this cycle over a total of 31 days. 2. We want to find out how many days you have worked in total during these 31 days. 3. Each cycle consists of $4 + 3 = 7$ days. 4. Calculate how many full 7-day cycles fit into 31 days: $$\frac{31}{7} = 4 \text{ full cycles with a remainder}.$$ 5. The number of full cycles is 4, and the remainder days are $$31 - 4 \times 7 = 31 - 28 = 3$$ days. 6. In each full cycle, you work 4 days, so total work days in full cycles: $$4 \times 4 = 16$$ days. 7. For the remaining 3 days, since you work 4 days then rest 3 days, the first 4 days are work days, so these 3 leftover days are all work days. 8. Add the leftover work days to the full cycle work days: $$16 + 3 = 19$$ days. Final answer: You have worked a total of **19 days** in 31 days.