Question

An experiment consists of rolling two fair number cubes. What is the probability that the sum of the two numbers will be >3

Answer 1

Answer:   $\bold{\dfrac{5}{12}}$

Step-by-step explanation:

greater than 3 means the sum is either 4, 5, or 6.

There are 15 permutations that meet the criteria:

(1, 3), (1, 4), (1, 5), (1,6)

(2, 2), (2, 3), (2, 4), (2, 5), (2,6)

(3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3,6)

(4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4,6)

(5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5,6)

(6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6,6)

There are 6²= 36 total permutations for 2 dice.

$Probability=\dfrac{\#\ of\ permutations> 3}{total\ \#\ of\ permutations}\\\\.\qquad \qquad =\dfrac{15}{36}\\\\.\qquad \qquad =\dfrac{5}{12}$