There are two beg first contains 10 white and 5 red balls, where as second beg contains 8 white an

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30 Nov 2010 Conditional Probability

There are two beg first contains 10 white and 5 red balls, where as second beg contains 8 white and 12 red ball.
A red ball is selected from one of the beg. what will be the probability of its coming from second beg.

OPtion

1) 1/3
2) 1/2
3) 5/13
4) 9/14
5) 3/5
6) 1/5
7) 5/14
8) 3/7
9) 7/13
10) 1

Solution

Required probability
P(sec/red) = { P(red/sec) . P(sec) }/ {(P(red/sec).P(s)+ P(Red/F).P(F))}
= (12/20 * 1/2)/(12/20*1/2 + 5/15 * 1/2)
= 9/14

Correct Option: 4 Best Solution (5)