Question

Picture attached please help

Answer 1

D

Explanation:

red blood cell = 0.000009 = 9 ×
`10^(-5)`

cold virus = 0.0000003 = 3 ×
`10^(-7)`

Divide diameter of red blood cell by diameter of cold virus

`(9(10^-5))/(3(10^-7 ))`

= 3 ×
`10^(-5-(-7))`

= 3
`10^(-5+7)`

= 3 × 10² → D