# CAT Quantitative Aptitude Questions | CAT Percentages Problems - Variables

###### CAT Questions | Percentage Questions | Percentage - Number of Balls CAT Questions

The question is from CAT Percentages. 2IIMs CAT question bank provides you with CAT questions that can help you gear for CAT Exam CAT 2020. This is a very interesting question from the topic percentages using Variables.In this question, we are given a bucket with a certain % of large and small balls along with certain % of different colours and we need to find the total no. of balls. It may seem to be a tough one to crack but its a simple, when you understand the concept.

Question 23 : A bucket has ‘a’ number of small and large balls out of which b% are black. Of the small balls, c% are black and of large balls, d% are black. Find the number of small balls in the bucket.

1. a * $$frac{$b - d$}{c + b - d}$ 2. a * $\frac{$b - d$}{c + b - 2d}$ 3. a * $\frac{$c - b$}{b - d}$ 4. a * $\frac{$b - d$}{c - d}$ ## Best CAT Online Coaching Try upto 40 hours for free Learn from the best! #### 2IIM : Best Online CAT Coaching. ## Best CAT Coaching in Chennai #### CAT Coaching in Chennai - CAT 2021Online Batches Available Now! ### Explanatory Answer ##### Method of solving this CAT Question from Percentages: Form the equations carefully and you are through! Let the number of small and large balls be S and L respectively => a = S + L ------- Equation$1)
Also, b% of a = c% of S + d% of L
=> ba = cS + dL
=> ba = cS + d(a - S) (Putting L = a – S from Equation(1))
=>( b – d) * a = (c – d) * S
=> S = a * $$frac{$b - d$}{c - d}$ The question is " Find the number of small balls in the bucket. ##### Hence, the answer is a * $\frac{$b - d$}{c - d}$ Choice D is the correct answer. ###### Best CAT Online Coaching Try upto 40 hours for free Learn from the best! ###### Best Indore IPM & Rohtak IPM CoachingSignup and sample 9 full classes for free. Register now! ###### Already have an Account? ###### CAT Coaching in ChennaiCAT 2021Enroll at 49,000/- 44,000/- Online Classroom Batches Starting Now! ###### Best CAT Coaching in ChennaiPrices slashed by Rs 4000/- Attend a Demo Class ##### 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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