1. Calculation of gaining ratio
old Ratio ( L, M and O) = 4:3:2
M retires from the firm.
New Ratio ( L and O ) = 5:3
Gaining Ratio = New Ratio - old ratio
2. Adjustment of goodwill
goodwill of the firm = Rs.72,000
This share of goodwill is to be debited to remaining parters's captial account in their gaining ratio (i,e,13:11)