A bag contains 5 blacks balls and 3 red balls. Two balls are picked at random without replacement. What is the probability that a black and red balls are picked?
-
15/28
- 13/28
- 5/14
- 3/14
The correct answer is: A
Explanation
Black balls = 5
Red balls = 3
P(B) = 5/8, P(R) = 3/8
P( a Black and a Red) = black ball and red ball or red ball and black ball i.e BR + RB
= (5/8) * (3/7) + (3/8) * (5/7)
= (15/56) + (15/56)
= 30/56
= 15/28