First off, you really don't need to write "what percent???" here.
25% of 80 is 0.25(80) = 20.
Step-by-step explanation:
The diameter of the bacterium is 10 times greater than that of the virus.
Answer:
A, B, E
Step-by-step explanation:

Divide both sides by 8.2

Correct choices:
A. 
B. The arrow points left.
E. There is a closed circle at 3.6.