Question

(a) A bag contains 8 red and 5 white balls. Two
successive draws of 3 balls are made at random
from the bag without replacements. Find the
probability that the first draw yields 3 white balls
and the second draw 3 red balls.
[5]​

Answer 1

Step-by-step explanation:

8 r, 5 w = 13 total balls

3 balls drawn successively twice, be the event E

total no of ways = 13c3×10c3

because:

when 3 balls are drawn at once from total 13 balls =13c3

when 3 balls are drawn again from remaining 10=13-3

is 10c3

no. ways event E can happen = 5c3×8c3

because:

no. ways 3white balls are drawn from 5 white=5c3

no. of ways 3red balls are drawn from 8 red =8c3

probability of event E = no. of ways of event E/ total no of ways

P(E)= 5c3×8c3/13c3×10c3

= 5×4×3×8×7×6/13×12×11×10×9×8

= 0.016

this is according to my knowledge in probability

I don't know about the answer but hope you understand the way it can be done