Answer:
0.5
Step-by-step explanation:
Let D be the event of selecting a marble with dots.
Let P be the event of selecting a purple marble.
The probability of selecting a marble with dots, P(D)=0.2
The probability of selecting a marble that is both purple and has dots, 
We want to determine the probability of selecting a purple marble given that the marble has dots on it, P(P|D)
By the definition of conditional probability:

The probability of selecting a purple marble given that the marble has dots on it is 0.5.
-5 here the answer is really good give me more like that
The correct answer is: [A]: " 3 * 10 ⁻⁷ " .
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Explanation:
To solve:
Given:
<u> (6 * 10⁻⁴ ) </u> = (6 ÷ 2) * 10⁽⁻⁴ ⁻³⁾ = 3 * 10 ⁻⁷ ; which is:
(2 * 10³ )
→ Answer choice: [A]: " 3 * 10 ⁻⁷ " .
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