Katie collects stamps. She has stamps from Canada, the U.S.A, and the rest of the world in a ratio of 1: 1.2: 1.5. She has 135 stamps from the rest of the world.
a) How many stamps are from Canada?
b) How many stamps are from the U.S.A?
c) What is the total number of stamps in Katie's collection?
(Please explain and show how you got those answers.)