Asked by A

A jar contains four blues marbles and two green marbles. Without looking, two marbles are drawn from the jar. What is the probability that two marbles with the same color will be selected?
Answered by PsyDAG
If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.

For blue = 4/6 * 3/5 = 2/5

For green = 2/6 * 1/5 = 1/10

Either-or probabilities are found by adding the individual probabilities.

2/5 + 1/10 = ?

Answered by A
2/5+1/10 is 5/10.

But in my book it states that the answer is 7/15, without an explanation.
Answered by Reiny
Either two blues or two greens

prob of 2 blues = (4/6)(3/5) = 2/5
prob of 2 grees = (2/6)(1/5) = 1/15 , this is where PsyDAG slipped up

so prob of 2 of same colour = 2/5 + 1/15 = 7/15
Answered by PsyDAG
⁄Mia Culpa! Sorry.
Answered by Anonymous
Why do u multiply by 3/5 and 1/5
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