1. Given: 27 men can complete the job in 15 days.
2. Calculate the total amount of work in terms of men-days:
W = 27 \times 15
3. Let \( x \) be the number of days required for 18 men to complete the same work. Therefore:
18 \times x = W
4. Equate the work from both scenarios:
27 \times 15 = 18 \times x
5. Solve for \( x \):
x = \frac{27 \times 15}{18}
x = 22.5 \text{ days}
6. Answer: 18 men can complete the job in x = 22.5 days.