Answer:
£1417.50
Explanation:
Dan & Colin share £9450 in the ratio 2 : 3
Dan's Share =

Dan then shares his part (£3780) between himself, his wife & their son in the ratio 3 : 4 : 1.
Total of their ratios = 3+4+1=8
The Wife's Share =

The Sons Share =

We are to determine how much more his wife get over their son.
The difference = 1890 - 472.50 =£1417.50
The wife gets £1417.50 much more than the son.