Calculation of New sharing

A:B:C = 2:2 1 (Old Ratio)

D is admitted for 1/6 the share while C will continue to rerain his original share (1/5)

This reaming share will be shared by A and B in the Ratio of 2:2 ( old ratio)*

*Since nothing is mentioned about the sacrifice made by the existing prartners, It is assumed that A and B sacrifice in their old Ratio,

Calculation of sacrificing Ratio