Algebraic ball counts after additions
Algebraic ball counts after additions
Secondary 2
2 marks
TGM Original Questions
Core stretch
A bag contains \(n\) white balls and \(2n\) black balls. One ball is selected at random.
- Write the probability of drawing white.[1]
- Five white and seven black balls are added. The probability of black is now \(\frac{5}{8}\). Find the initial number of black balls.[1]
Solution:
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Answer:(a) \(\frac{1}{3}\) (b) \(8\) black balls.
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