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KVPY2012MathematicsProbability

A purse contains 4 copper coins and 3 silver coins. A second purse contains 6 copper coins and 4 silver coins. A purse is chosen randomly and a coin is taken out of it. What is the probahility that it is a copper coin

Options

  1. A41 / 70
  2. B31 / 70
  3. C27 / 70
  4. D1 / 3

Correct answer

A. 41 / 70

Step-by-step solution

array l P ₁: 4 copper coins 3 silver coins P ₂: 6 copper coins & 4 silver coins E = Event of copper coin P ( E )= P ( P ₁ ) . P ( E / P ₁ )+ P ( P ₂ ) P ( E / P ₂ ) = 1 2 4 7 + 1 2 6 10 = 41 70 array

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