Given,
In bag 1\rightarrow 3R,4B&3W
And in bag 2\rightarrow 2R,5B&2W
Let A: Drawn ball from bag II is black
And let B: Red ball transferred
Now by total probability theorem we have P(A)=93×105+94×106+93×105=9054
And P(A∩B)=93×105
So, by bayes theorem we have, P(AB)=P(A)P(A∩B)
=93×105+94×106+93×10593×105
=15+24+1515=5415=185