Answer:
28
Explanation:
To complete the task in 30 days, they need at least 4 people working 7 hours.
( 4 x 7 = 28 hrs/day, 28 hrs/day to complete in 30 days, 28 x 30 = 840 hrs total to complete in 30 days. )
The company decides to have 5 people working 6 hours a day.
( 5 x 6 = 30 hrs/day, ? days to complete, must be 840 hours (30 day time span) to finish.
= 28. )