6 ta ishchi bir ishni 20 kunda bajaradi. Xuddi shu ishni 8 kunda bajarish uchun nechta ishchi kerak?

This is an inverse proportion problem. The total amount of work is constant. Let W be the total work.

Work = Number of workers × Number of days

First, calculate the total work:

\[ W = 6 \text{ workers} \times 20 \text{ days} = 120 \text{ worker-days} \]

Now, we want to complete the same amount of work (120 worker-days) in 8 days. Let 'n' be the number of workers needed.

\[ W = n \text{ workers} \times 8 \text{ days} \]

\[ 120 \text{ worker-days} = n \times 8 \text{ days} \]

To find 'n', divide the total work by the new number of days:

\[ n = \frac{120 \text{ worker-days}}{8 \text{ days}} = 15 \text{ workers} \]

Therefore, 15 workers are needed to complete the job in 8 days.

Ответ: 15