Hi Mayank,

Thank you very much for this question. I would be happy to share the solution to it:

• First of all, the calculation is correct: (5% ÷ 3) + 5% ≈ 1.67% + 5% ≈ 6.67%.
• The reason why you need to run the calculation this way is simple: In section “Background”, it is stated “The average lifetime of these four products is three years.” Since RetailBankingCo has to pay the closing commission only once, the revenue impact of this commission needs to be divided by 3, while the trailing commission of 5% needs to be paid on a yearly basis.

If you would like a more detailed discussion on how to best prepare for your upcoming interviews, please don't hesitate to contact me directly.

Best,

Hagen

(edited)