Computation of qualifying asset

HI

Need your assistance in letting me now how the interest amount was derived in the below answer

The question is

An amount of Rs.20,00,000/- was incurred for construction of a building and it was ready for occupation on 31.12.2011. The construction expenditure was incurred out of working capital facilities availed from the bank. Interest payable to it @ 15% p.a. The average working capital loan has never fallen below Rs.25 lakhs during the construction period. The details of expenditure incurred are as follows

July 2011 Rs.3,00,000/- August Rs.4,50,000/- September Rs.2,00,000/- October - Rs.5,00,000/- November - Rs.3,00,000/- and December - Rs.2,50,000/-.

Calculate the value of the Qualifying Asset?

Answer :

Month              Expenditure on Qualifying Asset           Interest                   Cummulative Expenditure including interest

July 2011                   3,00,000/-                                    NIL                                       Rs.3,00,000/-

Aug 2011                 4,50,000/-                                  Rs.3750/-                            Rs.7,53,750/-

Sep 2011                  2,00,000/-                                 Rs.9,422/-                            Rs.9,63,172/-

Oct 2011                  5,00,000/-                                 Rs.12,040/-                          Rs.14,75,212

NOv 2011                3,00,000/-                                Rs,18,440/-                           Rs.17,93,652/-

Dec 2011                2,50,000/-                                 Rs.22,421/-                         Rs20,66,073/

I dont understand why interest for July 2011 is not calculated and how the figure of 9422/- and 12040/- was calculated.

Regards