Answer:
140
Explanation:
- 143,622 bacteria present on day 15
- the bacteria doubles twice a day
that means each day backwards, the bacteria is four times less the day before
therefore:
- on day 14, the number of bacteria is 143,622 / 4
which is 35,905.5
and so on!
so:
- day 13 = 8,976.375
- day 12 = 2,244.09375
- day 11 = 561.0234375
- day 10 = 140.255859375
this rounded to the nearest whole number is
= 140 bacteria
(you can't have a part of a bacteria!)
hope this helps! :)