If 100 men can do 100 jobs in 100 days, 1 man can do one job in how many days ?

Answer

To solve the problem, we need to determine how many days it would take for 1 man to complete 1 job given that 100 men can complete 100 jobs in 100 days.

### Step-by-Step Solution:

1. **Understanding the Given Information:**
- 100 men can complete 100 jobs in 100 days.
- We need to find out how many days it takes for 1 man to complete 1 job.

2. **Setting Up the Relationship:**
- Let's denote:
- \( M_1 = 100 \) (number of men in the first scenario)
- \( D_1 = 100 \) (number of days in the first scenario)
- \( W_1 = 100 \) (number of jobs in the first scenario)
- \( M_2 = 1 \) (number of men in the second scenario)
- \( W_2 = 1 \) (number of jobs in the second scenario)
- \( D_2 \) (number of days in the second scenario, which we need to find)

3. **Using the Work Formula:**
- We can use the formula relating men, days, and work:
\[ \frac{M_1 \times D_1}{W_1} = \frac{M_2 \times D_2}{W_2} \]
- Plugging in the known values:
\[ \frac{100 \times 100}{100} = \frac{1 \times D_2}{1} \]

4. **Simplifying the Equation:**
- The left side simplifies to:
\[ 100 = D_2 \]
- Therefore, \( D_2 = 100 \).

5. **Conclusion:**
- It takes 100 days for 1 man to complete 1 job.

### Final Answer:
1 man can do 1 job in **100 days**.