If you are supposed to take pills at half an hour intervals, how many minutes would 5 pills last?

Answer 1

120 minutes:

1st pill at 0min
2nd pill at 30min.
3rd pill at 60min
4th pill at 90min.
5th pill at 120min.

Answer 2

2 hours ( you start by taking one )
p X p X p X p X p
p - pill
X- time interval of 30 minutes

Answer 3

the pills lasts for 2hours