Answer:
Part A) distance covered by the aligned red cells is: 180000 Km
Part B) 8000000 bacteria (8 million bacteria)
Step-by-step explanation:
Part A)
Let's first find the total number of red cells that the person has in the 5 liters, knowing that there are 4,500,000 of them in a cubic millimetre:
Since 1 liter contains 1,000,000 cubic millimetres, then, in 5 liters there must be 5 times that number of cubic millimetres. That is a total of 5,000,000 cubic millimetres.
Since in each cubic millimetre there are 4,500,000 red cells, then the number of red cells in the 5 liters must be the product of these two quantities:
4,500,000 x 5,000,000 = 22,500,000,000,000 red blood cells.
Now, to find the distance they will cover aligned one after the other, knowing that their average diameter is 0.008 mm is:
22,500,000,000,000 x 0.008 mm= 180000000000 mm
mm
In order to convert this distance into Km as requested, we use the fact that 1 mm = 0.000001 Km, or using exponents in base ten:
1 mm = 
Then, the distance covered in kilometers is:

Part B)
The vaccine contains a total of
bacteria per 
In order to find how many bacteria we have in 80
of the vaccine, we first need to convert 80
into
:

Then, if in one
there is
bacteria, in
there would be:
bacteria. That is:
bacteria = 8000000 bacteria (eight million bacteria)