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    Question

    The probability of selecting a rotten apple

    randomly from a heap of 100 apples is 0.20. What is the number of rotten apples in the heap?
    A 20 Correct Answer Incorrect Answer
    B 38 Correct Answer Incorrect Answer
    C 10 Correct Answer Incorrect Answer
    D 50 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Total number of apples in the heap = n(S) = 100
    Let E be the event of selecting a rotten apple from the heap.
    Number of outcomes favourable to E = n(E)
    P(E) = n(E)/n(S)
    0.20 = n(E)/100
    ⇒ n(E) = 100 × 0.20
    ⇒ n(E) = 20
    Therefore, the number of rotten apples in the heap = 20

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