what is the probability when a card is drawn 9 or 10

Решение

w ha t i s t h e p ro babi l i t y w h e n a c a r d i s d r a w n 9 or 10

\frac{2}{13}

десятичными цифрами

0.15384 \dots

Шаги решения

Find the probability of when a card is drawn 9:

\frac{1}{13}

Find the probability of 10:

\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}