**SOLUTION**

**Old Ratio (A, B and C) = 1/2 :2/5 : 1/10 or 5 : 4 : 1**

**As we can see, no information is given as to how A and B are acquiring C’s profit share after his retirement, so the new profit-sharing ratio between A and B is calculated just by crossing out the C’s share. That is, the new ratio becomes 5 : 4.****∴ New Profit Ratio (A and B) = 5 : 4**