Consider the circuit shown in the figure. Determine (a) the current in the 40 Ω resistor on the right, (b) the power at the voltage source, and (c) the power at the 8 Ω resistor. Knowing that the value of R = 0 Ω.

cant without the picture! ?

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 =