To find the expected number of green marbles Mr. Lim will pick in 50 trials, we need to know the total number of marbles and the proportion of green marbles in the bag.
Let's assume Mr. Lim has \( n \) marbles of each color: red, yellow, green, blue, and white. Since there are 5 colors, the total number of marbles is:
\[ \text{Total marbles} = 5n \]
The probability of picking a green marble in one trial is the number of green marbles divided by the total number of marbles:
\[ P(\text{green}) = \frac{n}{5n} = \frac{1}{5} \]
If Mr. Lim conducts 50 trials, the expected number of green marbles drawn can be calculated using the formula for expectation:
\[ E(\text{green}) = \text{Number of trials} \times P(\text{green}) = 50 \times \frac{1}{5} = 10 \]
Thus, Mr. Lim can expect to pick 10 green marbles.