Question

If two dice are thrown simultaneously find the probability of getting 7 or 11

Answer 1

Step-by-step explanation:

solution------>

Given :-

2 dice are thrown

if 2 dice are thrown simultaneously

all the possible

out come are as given below

s = (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 total number of all possible outcome=36

now ,

as per condition

1) probability of getting sum 7 or 11

the favourable out come are

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

(6,1)(6,5)

----->the number of favourable out come=8

Required probability

$\frac{8}{36} \\ \\ \frac{4}{18} \\ \\ \frac{2}{9}$

Answer 2

$\frac {2}{9}$ is required probability

Step-by-step explanation:

When two dices are thrown, the sample space is-

S = {(1,1)(1,2)(1,3)(1,4)(1,5)(1,6)}

      (2,1)(2,2)(2,3)....              (2,6)

      (3,1)(3,2)......                    (3,6)

      (4,1)...                               (4,6)

      (5,1)..                                (5,6)

      (6,1)...                               (6,6)

n(s) = 36

Pairs giving 7 as sum are - (1,6),(2,5),(3,4),(4,3),(5,2),(6,1) = 6 pairs

Pairs giving 11 as sum - (5,6) & (6,5) = 2 pairs

So, the favourable outcomes or probability for 7 & 11 = $\frac {8}{36} = \frac {2}{9}$