CAT Quantitative Aptitude Questions | CAT Permutation and Combination Questions

CAT Questions | Permutation Probability | Selection
CAT Questions

The question is from Permutation and Combination. This question is about Selection. We need to compute the probability of selecting a bag then a ball from it. This section hosts a number of questions which are on par with CAT questions in difficulty on CAT Permutation and Combination, and CAT Probability.

Question 29: A bag contains 4 red and 3 black balls. A second bag contains 2 red and 3 black balls. One bag is selected at random. If from the selected bag one ball is drawn, then what is the probability that the ball drawn is red?

1. $$frac{39}{70}\\$ 2. $\frac{41}{70}\\$ 3. $\frac{29}{70}\\$ 4. $\frac{17}{35}\\$ 2IIM : Best Online CAT Coaching 2IIM's Online CAT Coaching4000 off on CAT Online Course for CAT 2020. Vaild till Dec 16thCAT Online Coaching Best CAT Coaching in Chennai CAT Coaching in Chennai - CAT 2020Starts Sat, December 14th, 2019 Explanatory Answer Method of solving this CAT Question from Permutation and Combination: Clue - FInd the number of rearrangements and then focus on the number of digits Let Red balls be 'r' and brown balls be 'b' P$r) = p(b1) * p(r) + p(b2) * p(r)
P(R) = $$frac{1}{2}\\$ * $\frac{4}{7}\\$ + $\frac{1}{2}\\$ * $\frac{2}{5}\\$ P$R) = $$frac{17}{35}\\$ The question is "If from the selected bag one ball is drawn, then what is the probability that the ball drawn is red?" Hence the answer is "$\frac{17}{35}\\$" Choice D is the correct answer. 2IIM's Online CAT Coaching4000 off on CAT Online Course for CAT 2020. Vaild till Dec 16th Signup Now! Already have an Account? CAT Coaching in ChennaiCAT 2020Enroll at 44,000/- Next Weekend Batch Starts Sat, Dec 14th, 2019 Best CAT Coaching in ChennaiRegister Online, get Rs 4000/- off Attend a Demo Class CAT Preparation Online | CAT Permutation and Combination; Probability Videos On YouTube Other useful sources for Permutation and Combination Questions | Probability Questions Where is 2IIM located? 2IIM Online CAT Coaching A Fermat Education Initiative, 58/16, Indira Gandhi Street, Kaveri Rangan Nagar, Saligramam, Chennai 600 093 How to reach 2IIM? Phone:$91) 44 4505 8484
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