A die is thrown three times and the sum of the 3 numbers shown is 15. The probability that the first throw was a four, is

Explanation

To solve the problem, we need to find the probability that the first throw of a die was a 4, given that the sum of the three throws is 15. We can approach this problem step-by-step.

### Step 1: Identify the total outcomes
When a die is thrown three times, the total number of outcomes is \(6^3\) since there are 6 faces on a die and each throw is independent.

\[ \text{Total outcomes} = 6 \times 6 \times 6 = 216 \]
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