Mr. Lin has a bag with some marbles colored red, yellow, green, blue, and white. The marbles are identical in number. Mr. Lin will conduct a chance experiment by randomly drawing a marble from the bag and then returning it after noting the color. Based on 50 trials, how many green marbles will Mr. Lin expect to pick?
Since the marbles are identical in number, the probability of picking a green marble in each trial is 1/5.
So, in 50 trials, Mr. Lin can expect to pick 50 * (1/5) = 10 green marbles.