- #1

kent davidge

- 933

- 56

## Homework Statement

Bob had a box containing 9 green balls and 1 white ball. A Bob's friend removed one ball from the box without telling Bob what was its color. Now what's the probability for Bob picking up one green ball from the box?

## Homework Equations

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Not aware of "formulas", I just use those I think are useful for the problem in question.

## The Attempt at a Solution

If Bob's friend removed the white ball, then the chance for Bob picking up a green ball is 9/9 = 100%.

If Bob's friend removed a green ball, then there's 8/9 chance.

But I would like to get one total probability, not two conditions like these.