Question

A bag contains some white and black balls. The probability of picking two white balls one
after other without replacement from that bag is . What will be the probability of
picking two black balls from that bag if bag can hold maximum 15 balls only?

Do it clearly pls

Answer 1

Answer:

4. 1/11

Explanation :

Wc2/ (B+W)c2 = 14/33

W (W-1)/(W+B)*(B+W-1) = 14/33

Now expressing 14/33 in the above format by multiplying 4 in numerator and denominator

W (W-1)/(W+B)*(B+W-1) = 8*7/12*11 (note = balls <15)

W =8

W+B =12 B =4

Probability = 4c2/12c2 = 1/11