1 votes 1 votes A box contains 4 red balls and 6 black balls .Three balls are selected randomly from the box one after another without replacement .The probability that the selected set contains one red ball and two black ball is A)1/20 B) 1/12 C) 3/10 D)1/2 Mathematical Logic probability engineering-mathematics discrete-mathematics + – Çșȇ ʛấẗẻ asked Jul 14, 2017 Çșȇ ʛấẗẻ 2.3k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 2 votes 2 votes D) 1/2 answer Use hypergeometric distribution. (4C1 * 6C2)/ 15C3. focus _GATE answered Jul 14, 2017 selected Aug 7, 2017 by focus _GATE focus _GATE comment Share Follow See all 0 reply Please log in or register to add a comment.
3 votes 3 votes The probability that the set contains one red ball and two black ball =P(red)*P(black)*P(black) 4/10*6/9*5/8 (Without Replacement)=1/6 Now there are 3 ways to draw the sequence =RBB BBR BRB Thus P(r and 2 b`s)=1/6 *3=1/2 saxena0612 answered Aug 2, 2017 saxena0612 comment Share Follow See all 0 reply Please log in or register to add a comment.