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marbles numbered from 1 to 12 are put in a bag. if marbles are not put back into the bag after being drawn, what is the probability of drawing two prime numbers in a row?

User Braudy
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1 Answer

7 votes

Answer:


P = (1)/(11)

Step-by-step explanation:

Given


Marbles = 12

Selection: Without replacement

Required

The probability of selecting 2 primes

Between 1 and 12, the prime digits are: 3, 5, 7 and 11

i.e. 4 prime digits

When the first marble is selected, the probability that it will be prime is:


P(1) = (4)/(12)

Since it is a selection without replacement, there are 3 primes left and 11 marbles in total.

The probability of selecting another prime is:


P(2) = (3)/(11)

The required probability is:


P = P(1) * P(2)


P = (4)/(12) * (3)/(11)


P = (1)/(11)

User Daniel Nastase
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