NCERT Class XI Mathematics - Probability - Solutions

(a) There are 52 cards in a pack.
⇒ Number of points in the sample space S = n(S) = 52
(b) Let E be the event of drawing an ace of spades.
There is only one ace of spade n(E) = 1 and n(S) = 52
∴ P (E) =

n(E)

n(S)

=

1

52

(c) (i) Let F be the event of drawing an ace. There are 4 aces in a pack of 52 cards. n(F) = 4, n(S) = 52
∴ P (E) =

n(F)

n(S)

=

4

52

=

1

13

(ii) Let G be the event of drawing a black card. There are 26 black cards.
n(G) = 26, n(S) = 52
∴ P (G) =

n(G)

n(S)

=

26

52

=

1

2