Understanding Interest on Drawings
To calculate the interest on drawings for Mr. B, who withdrew ₹10,000 at the end of each month from July 2015 to March 2016, we need to consider the time each withdrawal was outstanding until March 31, 2016.

Withdrawal Schedule
- July 2015: ₹10,000 (outstanding for 9 months)
- August 2015: ₹10,000 (outstanding for 8 months)
- September 2015: ₹10,000 (outstanding for 7 months)
- October 2015: ₹10,000 (outstanding for 6 months)
- November 2015: ₹10,000 (outstanding for 5 months)
- December 2015: ₹10,000 (outstanding for 4 months)
- January 2016: ₹10,000 (outstanding for 3 months)
- February 2016: ₹10,000 (outstanding for 2 months)
- March 2016: ₹10,000 (outstanding for 1 month)

Calculating Interest for Each Withdrawal
The formula for calculating interest is:

Interest = Principal × Rate × Time
Where:
- Principal = ₹10,000 (monthly withdrawal)
- Rate = 9% p.a. = 0.09
- Time is in years.

Calculations:
- July withdrawal: \(10,000 × 0.09 × \frac{9}{12} = ₹675\)
- August withdrawal: \(10,000 × 0.09 × \frac{8}{12} = ₹600\)
- September withdrawal: \(10,000 × 0.09 × \frac{7}{12} = ₹525\)
- October withdrawal: \(10,000 × 0.09 × \frac{6}{12} = ₹450\)
- November withdrawal: \(10,000 × 0.09 × \frac{5}{12} = ₹375\)
- December withdrawal: \(10,000 × 0.09 × \frac{4}{12} = ₹300\)
- January withdrawal: \(10,000 × 0.09 × \frac{3}{12} = ₹225\)
- February withdrawal: \(10,000 × 0.09 × \frac{2}{12} = ₹150\)
- March withdrawal: \(10,000 × 0.09 × \frac{1}{12} = ₹75\)

Total Interest Calculation
To find the total interest:
- Total Interest = ₹675 + ₹600 + ₹525 + ₹450 + ₹375 + ₹300 + ₹225 + ₹150 + ₹75 = ₹3,375
Thus, the total interest on Mr. B's drawings up to March 31, 2016, is **₹3,375**.