D-10-2d+7 = 8 + d- 10 -3d
d-2d-10+7 = 8-10 +d -3d
-d-3=-2-2d
-d+2d=3-2
d=1
Final answer: C. d=1
Answer:
A.
Step-by-step explanation:
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
Okay I can help you with your math!!