A box contains 15 large marbles and 11 small marbles. Each marble is either green or white. 8 of the large marbles are green, and 5 of the small marbles are white. If a marble is randomly selected from the box, what is the probability that it is small or green? Express your answer as a fraction or a decimal number rounded to four decimal places.

Respuesta :

Answer:

[tex]0.7308[/tex]

Step-by-step explanation:

Given: A box contains 15 large marbles and 11 small marbles. Each marble is either green or white. 8 of the large marbles are green, and 5 of the small marbles are white.

To find: probability that a marble randomly selected is small or green

Solution:

Total number of marbles = [tex]15+11=26[/tex]

Number of small marbles that are white = 5

Also, each marble is either green or white.

So,

Number of small marbles that are green = [tex]11-5=6[/tex]

Total number of green marbles = Number of large marbles that are green + Number of small marbles that are green

= [tex]8+6=14[/tex]

Probability = Number of favorable outcomes ÷ Total number of outcomes

Let E denotes the event that a marble selected is small.

Let F denotes the event that a marble selected is green.

P(E) = Number of small marbles ÷ Total number of marbles

       = [tex]\frac{11}{26}[/tex]

P(F) = Number of green marbles ÷ Total number of marbles

      = [tex]\frac{14}{26}[/tex]

P(E∩F) = [tex]\frac{6}{26}[/tex]

Probability that it is small or green = P(E∪F)

= P(E) + P(F) -P(E∩F)

= [tex]\frac{11}{26}+\frac{14}{26}-\frac{6}{26}[/tex]

[tex]=\frac{11+14-6}{26} \\\\ =\frac{19}{26} \\\\=0.7308[/tex]

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