1. **State the problem:** We have counters in a bag with colors blue, silver, and green in the ratio 1 : 5 : 3. 2. **What is asked:** Find the probability that a randomly picked counter is silver. 3. **Recall the formula for probability:** $$\text{Probability} = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}$$ 4. **Identify favorable outcomes:** The favorable outcomes are the silver counters, which correspond to 5 parts in the ratio. 5. **Calculate total parts:** Total parts = 1 (blue) + 5 (silver) + 3 (green) = 9. 6. **Write the probability as a fraction:** $$\frac{5}{9}$$ 7. **Simplify the fraction:** 5 and 9 have no common factors other than 1, so the fraction is already in simplest form. **Final answer:** The probability of picking a silver counter is $$\frac{5}{9}$$.