Question

B A pair of fair dice is rolled, If the sum of the spots is 7, determine the probability that one di showed a 2.

Answer 1

Answer:

$\text{Probability}=\frac{1}{3}$

Step-by-step explanation:

Given : A pair of fair dice is rolled, If the sum of the spots is 7.

To find : Determine the probability that one die showed a 2 ?

Solution :

A pair of fair dice is rolled the outcomes are,

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

(2, 1) (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)

The sum of the spots is 7 i.e. (4,3),(2,5),(5,2),(3,4),(1,6),(6,1).

Total possibility = 6

Favorable outcome is that one die showed a 2 i.e. (2,5),(5,2)= 2

The probability that one die showed a 2 is given by,

$\text{Probability}=\frac{\text{Favorable outcome}}{\text{Total outcome}}$

$\text{Probability}=\frac{2}{6}$

$\text{Probability}=\frac{1}{3}$