Explanation

Let's solve:

3 men = 6 boys (given)

1 man = 2 boys

Work done by 3 men or 6 boys in 20 days:

Let's calculate work done by 1 boy in 1 day:

6 boys * 20 days = 120 boy-days

Now, 6 men and 8 boys:

6 men = 6 * 2 = 12 boys

Total = 12 boys + 8 boys = 20 boys

Time taken = 120 boy-days / 20 boys = 6 days