Answer:
If we assume that everyone in the group is an owner, we would have
[tex]20*2=40[/tex] legs.
[tex]64-40=24[/tex] legs
Therefore, we need 24 more legs.
These 24 additional legs can be made from the difference of legs between the owners and dogs.
In this case, dogs have [tex]4-2=2[/tex] more legs than an owner.
24 ÷ 2 = 12.
There are 12 dogs in the group.