Student from a school is selected at random. X denotes that theselected student
ID: 2953796 • Letter: S
Question
Student from a school is selected at random. X denotes that theselected student own a Visa Card. Y denotes that the selectedstudent own a Mastercard. Assume that 50% of all students own aVisa card and 40% own a Mastercard. Also 25% own both. A.) What is the probability that the randomly selected studenthas neither cards? B.) Are events X and Y independant? Justify your answer A.) What is the probability that the randomly selected studenthas neither cards? B.) Are events X and Y independant? Justify your answerExplanation / Answer
Given P(X) =0.5, P(Y)=0.4, P(X and Y) =0.25 (a) P(XUY)' = 1- P(X U Y) = 1- {P(X)+P(Y)-P(X and Y)} = 1-(0.5+0.4-0.25) = 0.35 (b) X and Y are not independent since P(X and Y)=0.25.