Answer: There are 252 different working groups of five that can be formed.
Step-by-step explanation:
Since we have given that
Number of workers = 12
Number of group of people to work together on a project = 5
Since Hugo and Viviana absolutely refuse, under any circumstances, to work together.
So, remaining number of workers = 12-2=10
so, we need to find the number of different groups of five that can be formed.
We will use "Combination":
[tex]^{10}C_5\\\\=252[/tex]
Hence, there are 252 different working groups of five that can be formed.