You can
put this solution on YOUR website!One virus takes up 8.5E-14 cc (cubic centimeters). N viruses take up 28 cc. Assuming that the viruses stack together and fill all of the space, set up a ratio.
Volume of one virus / One virus = Volume of N viruses / N viruses
Or using the information given,
8.5E-14 cc/1 virus = 28 cc/N (viruses)
Rearranging, by multiplying both sides by N and dividing by 8.5E-14, you get,
N = 28/8.5E-14 = 3.3E14 viruses.