A card is drawn at random from a deck of cards.whats is the probability at drawing ace or jacK

解

A c a r d i s d r a w n a t r an d o m f ro m a d ec k o f c a r d s . w ha t s i s t h e p ro babi l i t y a t d r a w in g a ce or ja cK

\frac{2}{13}

十進法表記

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解答ステップ

Find the probability of at drawing ace:

\frac{1}{13}

Find the probability of jacK:

\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}