At a certain pet shop, 1/3 of the pets are dogs and 1/5 of the pets are birds. How many of the pets are dogs?
(1) There are 30 birds at the pet shop.
(2) There are 20 more dogs than birds at the pet shop.
Lets say total number of pets in shop is 15x, the no of dogs is 5x and no of birds are 3x
stmt1: no of birds = 30 => 3x = 30 => x = 10 so no of dogs = 5x = 50 so sufficient
stmt2: 5x - 3x = 20 => 2x = 20 => x =10 so no of dogs = 5x = 50 so sufficient.
Hence both the statements are enough to answer.
My debrief: done-and-dusted-730-q49-v40