Which equation describes the fastest runner?
a. distance=0.5⋅time
b. distance=0.33⋅time
c. distance=time
d. distance=2⋅time

The equation distance describes the fastest runner.

Option D

Explanation:

The fastest runner is determined by how quick a person can reach the destination (i.e) in a less amount of time compared to others. Consider it took 10 seconds to the reach the destination x. Substitute time = 10 seconds,  

From the four options, the highest distance travelled for constant time is distance .

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 =