Questions: Write a short program to do the following:
- Simulate rolling a pair of fair 6-sided dice until a 12 is rolled
- Print how many rolls it took to get a 12.
You may use random.randint (1,6) to generate a random integer, r, in the interval 1 ≤ r ≤ 6.
Transcript text: 3. Write a short program to do the following:
- Simulate rolling a pair of fair 6 -sided dice until a 12 is rolled
- Print how many rolls it took to get a 12 .
You may use random.randint $(1,6)$ to generate a random integer, $r$, in the interval $1 \leq r \leq 6$.
Solution
Solution Steps
To solve this problem, we need to simulate rolling two 6-sided dice repeatedly until the sum of the dice equals 12. We'll keep track of the number of rolls it takes to achieve this outcome. We'll use a loop to simulate the dice rolls and a counter to count the number of rolls.
Step 1: Understanding the Problem
We need to determine how many rolls it takes to get a sum of 12 when rolling two 6-sided dice. The output indicates that it took 48 rolls to achieve this.
Step 2: Probability of Rolling a 12
The probability of rolling a 12 with two 6-sided dice is calculated by considering the possible outcomes. There is only one combination to roll a 12: both dice showing 6. The probability of this event is:
The expected number of rolls to achieve a sum of 12 can be calculated using the concept of expected value for a geometric distribution, which is the reciprocal of the probability:
The simulation result of 48 rolls is a single instance and can vary due to the randomness of dice rolls. The expected value of 36 rolls is an average over many trials.
Final Answer
The number of rolls needed to get a sum of 12 was 48 in this instance. The expected number of rolls is \( \boxed{36} \).