Hi Gaurav,
I think this is the circuit which you are talking about,
The one which I’ve posted earlier was actually a ‘theoritical circuit’, but the Boylestad’s circuit is a practical one. In theoritical circuit the positive of two cells are connected together which should not do in practical cases, since it can cause lot of problems.
In the above circuit the cells are connected in a normal way in which it should be and hence it is practical.
Now in the above circuit we have to assume that Vee is greater than Vbb (Vee > Vbb). Consider the point at which the negative of the Vbb and the positive of Vee are connected together, the collector is also connected to this point. Since Vee > Vbb the potential there will be not zero or negative, but positive when compared with the positive of Vbb. In this case the base will be less positive than the collector and the collector is more positive than the base. Hence the collectro base junction is reverse biased.
That was a very genuine and nice question from you and we expect more of this kind of queries.