Mass= density*volume
5*3 = 15 grams
It would be doubled, if 2000 is at 10 you add another 10 cm and you get 4000
The definition to parasitism is "the practice of living as a parasite in or on another organism." (Wikipedia). Therfore the answer to this is Ticks live on and drink blood from a cow, because this is the only option where an organism is living directly off another organism.
Hope I was most helpfull to you!