GMAT Data Sufficiency (DS) | Re: Of the 60 families in a certain neighborhood, 38 have a cat.

Good question. +1 to calreg11.

Mike is right that a double-matrix method is probably the easiest way to solve this problem and kys123 is right that the answer to the question is B(+1).

Of the 60 families in a certain neighborhood, 38 have a cat. How many of the families in this neighborhood have a dog?

Consider matrix below. Numbers in black are given and numbers in red arecalculated.
(1) 28 of the families in this neighborhood have a cat but not adog.