What number has exactly 6 factors

Which of the following parabolas opens up?

Which term describes the point where the perpendicular bisectors of the three sides of a triangle intersect?

Fracisco's game involves 3 green, 2 yellow, 4 red, and 3 black marbles. if he randomly draws three marbles from the bag, without replacement, what is the probability that he will draw yellow, and then red, and then black? a)1/192 b)1/72 c)3/220 d)1/55