contestada

A bag contains
10
marbles:
4
are green,
2
are red, and
4
are blue. Linda chooses a marble at random, and without putting it back, chooses another one at random. What is the probability that both marbles she chooses are blue? Write your answer as a fraction in simplest form.

Respuesta :

AL2006
Probability on the first draw is  (4 blue) / (10 marbles in the bag)  =  4/10.

She doesn't replace the blue marble, so

Probability on the 2nd draw is    (3 blue) / (9 marbles ion the bag) = 3/9.

Probability of BOTH events is

                              (4 · 3) / (10 · 9)

                         =      (12) / (90)

                         =          2 / 15

                         =  about  13.3% .

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