Question

a die is rolled once find the probability of getting (a) a prime number (b) number lying between 2and 6 (c) an odd number(d) a perfect square

Answer 1

Total no.of outcomes = 6 
(a) prime numbers = 2,3,5 
Probability of getting a prime number = 3/6 = 1/2
(b)numbers lying between 2 and 6 are 3,4,5 
Probability of getting a number which is lying in between  2 and 6 is = 3/6 = 1/2 
(c)odd numbers = 1,3,5
Probability of getting an odd number = 3/6 = 1/2
(d) perfect square numbers = 4
Probability of getting a perfect square number = 1/6

Answer 2

Total no.of outcomes = n(S) = 6
(i) Let E be the event of getting a prime number
n(E) = 3    [ 2,3,5 ]
p(E) = n(E)/n(S)
        = 3/6
        = 1/2
(ii) Let E be the event of getting a no lying between 2 and 6
n(E) = 3    [3,4,5]
p(E) = 3/6
        = 1/2
(iii) Let E be the event of getting an odd no
n(E) = 3    [ 1,3,5 ]
p(E) =3/6
        = 1/2
(iv) Let E be the event of getting a perfect square no
n(E) = 2   [ 1,4]
p(E) = 2/6
        = 1/3