An urn contains 5 red, and 2 green balls. A ball is chosen randomly and returned to the urn along with 6 more balls of the same color. Then, a ball is drawn again. Calculate the probability that the second ball is red (fraction in lowest terms).
An urn contains 5 red, and 2 green balls. A ball is chosen randomly and returned to the urn along with 6 more balls of the same color. Then, a ball is drawn again. Calculate the probability that the second ball is red (fraction in lowest terms).