Question:

Two dice are rolled. Then, the probability that the total score is a prime number is

Show Hint

For dice problems involving sums, first list all possible required sums and then count ordered pairs systematically.
Updated On: Jun 26, 2026
  • \(\dfrac{1}{16}\)
  • \(\dfrac{5}{12}\)
  • \(\dfrac{1}{2}\)
  • \(\dfrac{7}{9}\)
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Step 1: Find the total number of outcomes.
When two dice are rolled, each die has \[ 6 \] possible outcomes.
Therefore, total outcomes are \[ 6\times 6=36 \]

Step 2: Identify possible prime sums.
The minimum sum is \[ 1+1=2 \] and the maximum sum is \[ 6+6=12 \] Prime numbers between \(2\) and \(12\) are: \[ 2,3,5,7,11 \]

Step 3: Count outcomes for sum \(2\).
Possible outcome: \[ (1,1) \] So, number of outcomes is \[ 1 \]

Step 4: Count outcomes for sum \(3\), \(5\), \(7\), and \(11\).
For sum \(3\): \[ (1,2),(2,1) \] Number of outcomes: \[ 2 \] For sum \(5\): \[ (1,4),(2,3),(3,2),(4,1) \] Number of outcomes: \[ 4 \] For sum \(7\): \[ (1,6),(2,5),(3,4),(4,3),(5,2),(6,1) \] Number of outcomes: \[ 6 \] For sum \(11\): \[ (5,6),(6,5) \] Number of outcomes: \[ 2 \]

Step 5: Add all favorable outcomes.
Total favorable outcomes are \[ 1+2+4+6+2=15 \]

Step 6: Compute the probability.
\[ \text{Probability} = \frac{15}{36} \] \[ = \frac{5}{12} \]

Step 7: Final conclusion.
Therefore, \[ \boxed{\frac{5}{12}} \]
Was this answer helpful?
0
0