An urn contains one black ball and one green ball. A second urn contains one white and one green ball. One ball is drawn at random from each urn.
What is the probability that both balls are of same colour?

Options

A. `1//2`
B. `1//3`
C. `1//4`
D. `2//3`

Explanation

To solve the problem, we need to determine the probability that both balls drawn from the urns are of the same color. Let's break down the solution step by step.

### Step 1: Identify the contents of the urns
- **Urn 1** contains: 1 Black ball (B) and 1 Green ball (G).
- **Urn 2** contains: 1 White ball (W) and 1 Green ball (G).

### Step 2: List the possible outcomes
When we draw one ball from each urn, the possible combinations of the balls drawn are:
1. (B, W) - Black from Urn 1 and White from Urn 2
2. (B, G) - Black from Urn 1 and Green from Urn 2
3. (G, W) - Green from Urn 1 and White from Urn 2
4. (G, G) - Green from Urn 1 and Green from Urn 2

### Step 3: Identify the favorable outcomes
We are interested in the outcomes where both balls are of the same color. The favorable outcomes from our list are:
1. (G, G) - Both balls are Green.

### Step 4: Count the total outcomes and favorable outcomes
- Total outcomes = 4 (as listed above)
- Favorable outcomes = 1 (only (G, G))

### Step 5: Calculate the probability
The probability \( P \) that both balls are of the same color is given by the formula:
\[ P(\text{same color}) = \frac{\text{Number of favorable outcomes}}{\text{Total outcomes}} = \frac{1}{4} \]

### Final Answer
The probability that both balls are of the same color is \( \frac{1}{4} \).

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