Probability Part 1

An urn contains 5 red and 2 green balls. A ball isdrawn at random from the urn. If the drawn ballis green, then a red ball is added to the urn and ifthe drawn ball is red, then a green ball is addedto the urn; the original ball is not returned to theurn. Now, a second ball is drawn at random fromit. The probability that the second ball is red, is :