Population
I would probably say zero
In golf, the "foe" would be the number of strokes needed to get the ball into the hole. You're competing to see who can do that in the fewest number.
oligarchy government
Using standard American coins (1, 5, 10, 25 cents), the fewest number of coins to make $0.13 would be four -- one dime and three pennies. This number would be different in countries that use different denomination coins, such as the 2-cent piece.
They are all 4 sided quadrilaterals and the fewest lines to draw them are 4 straight lines joined together at 4 vertices.
Two, a square and a trapezoid. A square is a rectangle and a parallelogram.
27%
This would contain 50 protons.
There are 1,500 species sea stars...so eliminating them would decrease the number of species by 1,500. Any species that rely on sea stars for food will be adversely affected as well.
We would have to see the problem in order to know that.
They would be a population.
Paper cup uses the fewest resources from the environment.