a jar contains 8 yellow marbles and 12 marbles. anissa will select one marble from the jar without looking,place it on the table,and then select a second marble without looking. what is the probability thay she will select 2 green marbles from the jar.

Question

anonymous · Answer

there arnt any green marbles.. so there is a 0% chance of getting 2 green marbles

anonymous · Answer

lol

anonymous · Answer

good answer eh :D

anonymous · Answer

medal? :)

anonymous · Answer

Rubin, this does not exclude the logical possibility that 2 of the remaining 4/12 are green!

anonymous · Answer

No actual colour is stated for the remaining marbles..

anonymous · Answer

this is also a dependent probability question

anonymous · Answer

her chances of selecting the first green marble are 4/12, and her chances of selecting a second green marble are 3/11

anonymous · Answer

in probability we dont add the probabilities, we multiply. so her chances of selecting two green marbles are 4/12x 3/11=12/132.

anonymous · Answer

agree with BPDlkeme, as such there is not enough information regarding green marbles to make a specific answer.  
Although we could for each circumstance of possibilities of green marbles in the remaining 12 marbles give answers.

The dependency is critical though for the various other possibilities.  Are the 2 marbles taken out together, as that will affect the result.
Or after the first marble is taken out, is it placed back before the 2nd marble is taken out?
Thus there are now 24 different answers possible.

anonymous · Answer

by dependent, I mean the probability of selecting a second green marble "depends" on her selecting the first one, i.e this is take out, therefore the probability denminator reduces from 12 to 11

anonymous · Answer

shaunlampert has better described this "dependency" than I have...well done

anonymous · Answer

however, the answer is still 12/132

anonymous · Answer

Perhaps the medal should go to shaun for an excellent explanation, he clearly understands the principles of probability

anonymous · Answer

Rubin, no offence mate, you didnt think this one through..

anonymous · Answer

give one to BPDlkeme then, (I don't need one particularly as I am a teacher)

anonymous · Answer

snap shaun!

anonymous · Answer

perhaps it should be shared then - lol.