Question

How can we determine key words to find what kind of sign to use

Answer 1

The problem says there are:

2 neighbors with birds

10 neighbors with cats

8 neighbors with dogs.

As each neighbor owns only one pet, the total number of neighbors is then:

2+10+8=20

The percentage of the neighbors that own dogs is the number of neighbors with dogs, divided by the total number of neighbors, then:

`(8)/(20)*100=(4)/(10)*100\text{ \%=0.4x100\%=40\%}`

Then the 40% of the neighborhood pet owners have dogs.