Question

A bag contains 4 blue balls, 7 yellow balls and 4 white balls. Event A is defined as drawing a blue ball on the first draw and event B is defined as drawing a white ball on the second draw.
If two balls are drawn from the bag, one after the other and not replaced, what is P(B|A) expressed in simplest form?

A. 2/7
B. 3/14
C. 4/15
D. 4/11

Answer 1

P(B|A) is defined as P(A and B)/P(B)
P(A and B) = P(A) * P(B)
= (4/15)(4/15) = 16/225

P(B|A) = (16/225) ÷ (4/15)
= (16/225)(15/4) = 4/15

Answer 2

thank you