A patient has 600 thousand bacteria, and none are resistant…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A patient has thousand bacteria, and none are resistant. A medicine halves the number of bacteria every day. How many thousand bacteria are left after days? How many after days?
Need a reminder? The key ideaShow
Treatment can ease the symptoms or kill the cause. Antibiotics block steps that bacteria need, such as building a cell wall, and do not work on viruses. Resistant bacteria survive an unfinished course and multiply. Prevention uses general ways, such as clean water and no stagnant water, and the specific way of immunisation.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Four days. thousand.
Step 2. Six days. Two more halvings: thousand.
Answer: thousand after days and thousand after days. If a few bacteria were resistant, the fall would stop at their number.
Discussion (0)
Log in to join the discussion.
Loading…