A bag B1 has 3 white balls and 2 red balls. Another bag B2 has 4 white and 6 red balls. A ball is drawn randomly from bag B1 and with out seeing it’s colour, is being put in bag B2. Now a ball is drawn from bag B2. The probability of both the drawn balls, of being same colour, is
Answer & explanation
Correct answer: option 3
E1 : Ball drawn from B1 is white.
E2 : Ball drawn from B1 is red.
A : Both the drawn balls are of same colour.
$P(A)=P\left(E_1\right) . P\left(A / E_1\right)+P\left(E_2\right) . P\left(A / E_2\right)$
$=\frac{3}{5} . \frac{5}{11}+\frac{2}{5} . \frac{7}{11}=\frac{29}{55}$