MDM4U8 Name: __________________________ Date: __________________
QUIZ: Probability Distributions
• Do not begin this paper until instructed to do so.
• Unless otherwise stated in the question, all numerical answers should be given exactly or correct
to three significant figures.
• For full marks, show all your work and use proper notation.
1. A test has five questions. To pass the test, at least three of the questions must be answered correctly.
The probability that Maya answers a question correctly is 20%. Let X be the number of questions
that Maya answers correctly.
(a) Find E(X). (1)
(b) Find the probability that Maya passes the test. (2)
for x = 0, 1, 2, 3 is a probability distribution function.
(a) Find k. (3)
(b) Find P(X ≥ 1). (2)