# 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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