Find the acceleration of a northbound subway train that slows down from 15 m/s to 10 m/s in 0.9 s. O A. 16.66 m/s2 O B. - 5.55 m/s? OC -0.61 m/s2 O D. 5.55 m/s2​

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 =