Answer
Find out the what is the new ratio of the number of geese to the number of hens .
To prove
As given
There are 6 geese and 9 hens on Mr. Thomson’s farm.
Mr. Thomson adds 6 more geese and 3 more hens to his farm.
Than
The number of geese becomes = 6 + 6
= 12
The number of hens becomes = 9 +3
= 12
The new ratio of the number of geese to the number of hens be

simplify

Therefore the new ratio of the number of geese to the number of hens be 1:1 .