What is the Probability of Owning Either a Microwave or CD Player?

[Calculator14]

Homework Statement

The probability that Joe owns a microwave oven is 75%; the probability that he owns a CD player is 45%; and the probability that he owns both is 40%. Find the probability that he owns either one but not both.

Homework Equations

(work posted below)

The Attempt at a Solution

P(only microwave)= .75-.4 = .35
P(only CD Player) = .45 - .4 = .05
P(only micr. or CD Pl) = .35 + .05 = .4

Answer = .4

 

[obafgkmrns]

You got it! Try visualizing it with a Venn diagram: 2 overlapping circles representing probabilities that he owns either or both, surrounded by a large circle that represents probability that he owns either, both, or neither. (Hint: probability he owns neither is 0.2)