Retirement please tell

Solution:-

C's share = 1/4

C's share taken by A and B equally= 1/4×1/2 = 1/8
 So, A get 1/8 share
B get 1/8 share

New ratio = old ratio + gaining ratio 
A = 2/4 + 1/8= 5/8

B = 1/4 + 1/8 = 3/8


New ratio of A and B = 5:3