{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

mt1sol1 - York University MATH 2030 3.0AF(Elementary...

This preview shows pages 1–2. Sign up to view the full content.

York University MATH 2030 3.0AF (Elementary Probability) Midterm Exam I – SOLUTIONS October 17, 2008 NAME: STUDENT NUMBER: You have 50 minutes to complete the examination. There are 4 pages, containing 5 questions. You may bring one letter-sized two-sided formula sheet to the exam. No other books or notes may be used. You may use a calculator. Show all your work, and explain or justify your answers. You may leave numerical answers unsimplified, including binomial coefficients. Use the back of your page if you run out of room. 1. [20] An urn has 15 red balls and 20 yellow balls. You choose 4 balls at random, without replacement. Find P (at most 3 red balls are chosen | at least 3 red balls are chosen) Solution: P (at most 3 red | at least 3 red) = P (at most 3 red and at least 3 red) P (at least 3 red) = P (exactly 3 red) P (at least 3 red) = P (exactly 3 red) P (exactly 3 red) + P (exactly 4 red) = ( 15 3 )( 20 1 ) ( 35 4 ) ( 15 3 )( 20 1 ) ( 35 4 ) + ( 15 4 )( 20 0 ) ( 35 4 ) = ( 15 3 )( 20 1 ) ( 15 3 )( 20 1 ) + ( 15 4 )( 20 0 ) = 9100 10465 = 20 23 0 . 8696 2. [20] A, B, C are independent events, and P ( A ) = 0 . 6, P ( B ) = 0 . 7, P ( C ) = 0 . 8; Let D

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern