Question 983074
There are 60 minutes in each hour so you have a total of 420 minutes.
Each person could complete {{{420/45=9.3}}} tasks in the 7 hours.
Rounding down makes it 9 tasks.
So you need,
{{{400/9=44.4}}} persons.
Rounding up to 45 persons will ensure that you complete the 400 tasks in less than 7 hours.