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You select a marble without looking and then put it back. If you do this 24 times, what is the

best prediction possible for the number of times you will pick a marble that is not orange?
times

You select a marble without looking and then put it back. If you do this 24 times-example-1
User Tony Brix
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1 Answer

1 vote

Explanation:

24 times, as there are no orange marbles in the set.

so, every pull will produce a marble that is not orange with 100% certainty.

in general, we have 12 marbles.

let's change the problem description into picking a marbles that is not blue.

we have 6 blue marbles.

the chance to pick a blue marble is therefore 6/12 = 1/2.

and the probability to not pick a blue marbles is 1 - 1/2 = 1/2.

so, in 24 pulls, we expect 24× 1/2 = 12 times to get a marble that is not blue.

or change it to "not green" marbles.

5 green marbles.

the probability to pick a green marble is 5/12.

the probabilty to not pick a green marble = 1 - 5/12 = 7/12.

in 24 pulls we expect 24 × 7/12 = 14 times to get a marble that is not green.

it change it to "not purple" marbles.

1 purple marble.

the probability to pick a purple marble is 1/12.

the probabilty to not pick a purple marble = 1 - 1/12 = 11/12.

in 24 pulls we expect 24 × 11/12 = 22 times to get a marble that is not purple.

User Mickmackusa
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