You randomly select one card from a 52-card deck. Find the probability of selecting a two or a six.

解

Y o u r an d o m l y se l ec t o n e c a r d f ro m a 52 - c a r d d ec k . F in d t h e p ro babi l i t y o f se l ec t in g a tw o or a s i x .

\frac{2}{13}

十進法表記

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解答ステップ

Find the probability of selecting a 2:

\frac{1}{13}

Find the probability of a 6:

\frac{1}{13}

Since the events are disjoint, Use the formula

P (X_{1} \lor X_{2} \lor \dots \lor X_{k}) = P (X_{1}) + P (X_{2}) + \dots + P (X_{k})

= \frac{1}{13} + \frac{1}{13}

\frac{1}{13} + \frac{1}{13} = \frac{2}{13}

= \frac{2}{13}