Whatt? the answer is 7z+84
there is not a single X in the equation i really dont know where you got the X
Answer:
im not sure but i think its 29%
Sadly there is no way to graph properly on this website.
20 total marbles....7 are green
probability on first draw is 7/20...and since the marble was not replaced, the probability on the second draw is 6/19. And since they cant happen at the same time, we multiply
7/20 * 6/19 = 42/380 which reduces to 21/190