Answer:
302.4 days
Explanation:
You bring back 10 every 2 weeks, then the rate is:
R = (10 people)/(2 weeks) = (10/2) people per week = 5 people per week.
This means that you bring back 5 people per week.
Now, you have 216 people, and you bring back 5 of them each week, then the amount of people that you have as a function of time, w, in weeks, is:
P(w) = 216 - 5*w
You will have them all back when:
P(w) = 0
Then we can solve it for w:
P(w) = 0 = 216 - 5*w
5*w = 216
w = 216/5 = 43.2
the time is 43.2 weeks.
We could write this in days, because we know that each week has 7 days, then 43.2 weeks is equal to 43.2 times 7 days, this is:
(43.2)*7 days = 302.4 days