1 votes 1 votes Ten percent of screws produced in a certain factory turn out to be defective. Find the probability that in a sample of 10 screws chosen at random, exactly two will be defective. a) 0.2 b) 0.25 c) 0.8 d) 0.3 79. Probability isro-ee probability + – sh!va asked Mar 10, 2017 retagged Mar 7, 2019 by Naveen Kumar 3 sh!va 3.8k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes We can apply here BINOMIAL DISTRIBUTION, Prob [defective] = 0.1 Prob [non defective] = 0.9 n = 10 r = 2 {exactly 2} Binomial Distribution :- nCr * (p)^r * (q)^(n-r) 10C2 * 0.1^2 * 0.9^8 0.1937102445 or 0.2 Hence a) 0.2 is correct answer. Shubhanshu answered Mar 10, 2017 Shubhanshu comment Share Follow See all 7 Comments See all 7 7 Comments reply Show 4 previous comments Rahul Jain25 commented Mar 11, 2017 reply Follow Share But binomial is not correct approach. 0 votes 0 votes Shubhanshu commented Mar 11, 2017 reply Follow Share Please tell me why??? 0 votes 0 votes E KRISHNA THEJA commented Jan 1, 2020 reply Follow Share Because calculator is not allowed in the examination. 0 votes 0 votes Please log in or register to add a comment.