find how many minutes until one is left. That one leaves immediately if the first ones left at t = 0
a(n+1) = (1/2)A(n)
a(1) = 256
a(N) = 1
an = a1 r^n-1
1 = 256 *.5^(n-1)
.5^(n-1) = 1/256
(n-1) log .5 = log (1/256)
n-1 = 8
n = 9
so 9 * 5 min = 45 min
if the first ones left at the END of the first five minutes then the last one leaves after 50 minutes
There were 256 people at a fundraiser. When the event was over, half of the people who remained left every 5 minutes.
How long after the event ended did the last person leave?
1 answer