CAT Practice : Percents, Profits

Number of Balls

Number of Balls

    Q.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.


  • Correct Answer
    Choice D.

Detailed Solution

Let the number of small and large balls be S and L respectively

= ) a = S + L………………..(1)

Also, b% of a = c% of S + d% of L

= ) ba = cS + dL

= ) ba = cS + d(a - S) (Putting L = a – S from (1))

= )( b – d) * a = (c – d) * S

= ) S =

Correct Answer:

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