Final answer:
A can complete two-thirds or about 66.67% of the work in 4 days, assuming the work done each day is the same.
Step-by-step explanation:
If A can complete work in 6 days, we must first understand that completing the work would represent 100% of the task.
Since the work is spread evenly over the days, we can divide the total work by the number of days it takes to complete it, which gives us the fraction of the work done per day.
So, for each day, A completes 1/6 (approximately 16.67%) of the work.
In 4 days, A would complete:
4 days * (1/6 work/day) = 4/6 or 2/3 which is about 66.67% of the total work.
Therefore, after 4 days, A would have completed two-thirds of the work.