During a one-hour trip, a small boat travels 80.0 km north and then travels 60.0 km east. (a). What is the boat's average speed during the one-hour trip?
(b). What is the magnitude and direction of the boat's average velocity for one hour trip?

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 =

the answer is 100. i just did this lesson and got a 100% on it. : )

-fishtank