iran-konkur 2022 Q127

iran-konkur · Other · konkur-riazi_1401_specialized Conditional Probability Combinatorial Conditional Probability (Counting-Based)
127-- In a bag there are 16 balls numbered 1 to 16. Two balls are drawn randomly and without replacement. If we know that the number of the second ball is less than the number of the first ball, what is the probability that the number of the first ball is 16?
(1) $\dfrac{1}{16}$ (2) $\dfrac{1}{12}$ (3) $\dfrac{1}{8}$ (4) $\dfrac{1}{4}$
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\textbf{127--} In a bag there are 16 balls numbered 1 to 16. Two balls are drawn randomly and without replacement. If we know that the number of the second ball is less than the number of the first ball, what is the probability that the number of the first ball is 16?

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(1) $\dfrac{1}{16}$ \hfill (2) $\dfrac{1}{12}$ \hfill (3) $\dfrac{1}{8}$ \hfill (4) $\dfrac{1}{4}$



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