Question

Two dice are throvm simultaneously and the sum of numbers appearing on them is noted. Find the probability that sum is (i) 7 (ii) 9.

Answer 1

Solution :

In a throw of two dice ,

the number of possible outcomes are

6 × 6 = 36 -----( 1 )

i )Let E denote the event of getting

sum 7 .

Favourable outcomes (sum of numbers

appearing on them is 7) = { (1,6,),(6,1),(2,5),

(5,2),( 3,4 ), ( 4,3 )}

Number of favourable outcomes = 6

P(E) = 6/36 = 1/6

ii )Let E denote the event of getting

a sum 9.

Favourable outcomes( sum of Numbers

appearing on them is 9) = { (3,6,),(6,3),

( 4,5 ) ,( 5 , 4 ) }

Number of favourable outcomes = 4

P( E ) = 4/36

= 1/9

••••••

Answer 2

Answer:

(i) 1/6 (ii) 1/9

Step-by-step explanation:

Find the total number of possible outcomes:

Total number of outcomes = 6 x 6 = 36

Find the probability that the sum is 7:

Total number of favourable outcome = 6

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

P(Sum is 7) = 6/36 = 1/6

Find the probability that the sum is 9:

Total number of favourable outcomes = 4

They are (3, 6)(4, 5)(5,4), (6,3)

P(Sum is 9) = 4/36 = 1/9

Answer: (i) 1/6 (ii) 1/9