You have two boxes of colored pens. the first box contains a red pen, a blue pen, and a green pen. the second box contains a yellow pen, a red pen, and a black pen. what is the set that represents all the pens?
a.{red pen, blue pen, green pen}
b.{red pen}
c.{red pen, red pen, green pen, yellow pen, black pen}
d.{red pen, blue pen, green pen, yellow pen, black pen}

Need to finish my juan wants to build a greenhouse in his back yard. he needs to maximize the ratio of floor area to structure volume in order to provide the most room for plants while minimizing the area to be heated. find the description of the structure that best meets juan’s criteria. a.) a hemisphere with a diameter of 12 feet b.) a cube with a side length of 12 feet c.) a cone with a diameter of 12 feet and a height of 10 feet d.) a square pyramid with a base side length of 12 feet and a height of 9 feet