The total drawings at the end of each quarter = rupee 9,000.
The average period for quarterly drawings = 7.5 months (or 7.5/12 years). \[ \text{Interest} = \text{Total Drawings} \times {Rate} \times {Time} \] \[ \text{Interest} = rupee 36,000 \times 6\% \times \frac{7.5}{12} = rupee 810 \]

A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?