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

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

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 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 ) ( 35 4 ) = ( 15 3 )( 20 1 ) ( 15 3...
View Full Document

Page1 / 3

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

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online