The answer is 15.7079632679
Answer:
option D is the right answer
Number of red marbles in bag = r. b = 10-rProbability of first marble being red: r/10Second marble being red: (r-1)/9total probability = 2/15 = (r-1)*r/90r = 4b = 6
The formula of a distance between two points A and B is :

You should this formula by heart.
Then, you just have to apply it ! :D
Here :




Therefore :




In short, the answer would be the first option :

.
Hope this helps !
Photon
Answer:
+180
Step-by-step explanation: