A leading cosmetics manufacturer advertises its product in three magazines: Magazine X, Magazine Y and Magazine Z. A survey of 500 customers by the manufacturer reveals the following information on the number of people learning of the product from each of the magazines:
Magazine X: 180
Magazine Y: 200
Magazine Z: 192
Some of these people came to know about the product from two or more magazines. The numbers by this classification are
Magazine X and Magazine Y: 84.
Magazine X and Magazine Z: 52
Magazine Y and Magazine Z: 64.
All three: 38.
a) Show these numbers in a Venn diagram.
b) How many of the customers saw the advertisement in:
(i) at least one magazine?
(ii) exactly one magazine?
July 29th 2007, 04:52 PM
For b(i) all 500 people saw the advertisement in at least one magazine.
b(ii) You have to subtract out the 'and' numbers to get the numbers for X,Y,Z. Then add all of these up.