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View Full Version : Probability


JPCRS
Jun 20, 2011, 10:55 AM
A hamburger chain found that 75% of all customers use mustard, 80% use ketchup, and 65% use both, when ordering a hamburger. What are the probabilities that
a) A ketchup-user uses mustard?
b) A mustard-user uses ketchup?

Unknown008
Jun 20, 2011, 12:05 PM
What have you tried? Did you draw a Venn diagram or a probability tree to help you?