What are 2 laws of reflection

The two laws of reflection are as follows: ... The incidenct ray, the reflected ray, and the normal to the reflecting interface at the point of incidence all lie in the same plane. 2. The angle of incidence equals the angle of reflection.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =