A bag contains 3 red marbles and 4 blue marbles. a marble is taken at random and replaced. Another marble is taken from the bag. Work out the probability that the two marbles taken from the bag are the same color.
<span>Total number of marbles in the bag is 3 + 4 = 7.<span>The problem asks for the probability of (RR) or (BB).</span>It's worthy to note we are replacing the balls after each draw, which means we always have 7 to draw from</span>Since each draw is independent, we take the product of each event for the total event probability.
