Solvng transistor circuit

The transistor circuit in shown in the schematic I have included:

^{simulate this circuit – Schematic created using CircuitLab}

I have tried solving it like this:

First I calculated the potential at node A by applying voltage divider law:

V(A)=(680/680+4.7)*20. The answer is 19.86V. Now, applying KVL in input loop:

19.86=Ib*R2+0.7V. And this gives the value of Ib to be 0.028mA.
But my text book has the value of Ib=15.45 microA. Why am I getting this much difference in the base current?(Which ultimately causes lots of difference in collector current if gain is high). This is how the textbook has solved it:

I dont know where I am getting it wrong. Would be of great help if someone corrected me. Thanks in advance...