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.

P(RR) = 3/7 * 3/7 = 9/49

P(BB) = 4/7 * 4/7 = 16/49

We want to know P(RR) + P(BB)

P(RR) + P(BB) = 9/49 + 16/49 = 25/49

- Total number of marbles in the bag is 3 + 4 = 7.
- The problem asks for the probability of (RR)
*or*(BB). - It's worthy to note we are replacing the balls after each draw, which means we always have 7 to draw from

P(RR) = 3/7 * 3/7 = 9/49

P(BB) = 4/7 * 4/7 = 16/49

We want to know P(RR) + P(BB)

P(RR) + P(BB) = 9/49 + 16/49 = 25/49

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