Profit after interest on capital and salary is Rs 2,20,000. A partner is entitled to 10 per cent commission on profit after charging such commission. The commission is:

1. Where the commission is a percentage of profit after charging such commission, the base already excludes the commission itself. 2. The formula the textbook prints is profit times the rate divided by one hundred plus the rate. 3. Here that is Rs 2,20,000 times 10 divided by 110. 4. That gives a commission of Rs 20,000. 5. Checking, Rs 2,20,000 minus Rs 20,000 leaves Rs 2,00,000, and 10 per cent of Rs 2,00,000 is indeed Rs 20,000. 6. Option A applies the before-charging formula instead, which is the single most common error on this topic. _Source: TN HSC Class 12 Accountancy (Samacheer Kalvi, Govt of Tamil Nadu), Unit 3 "Accounts of Partnership Firms - Fundamentals", §3.8 and Illustration 23_