In: Statistics and Probability
Ahandofsevencards isdealt from adeck of 52 cards. (a) Howmanyhandsarepossible? (b) Howmanyhandsthatcontainexactly2diamonds arepossible? (c) Howmanyhandswith2diamondsand3spadesarepossible?
a. There are total 52 cards in a deck . We are drawing 7 cards out of them .
We can draw 7 cards from 52 in 
different ways.
Then total number of different possible hands is given by
 =
133784560
b. Now we will choose 7 cards out of which 2 is diamond.
There are total 13 card of diamond. So we will choose 2 from
this 13 cards in 
ways and  remaining 5 card from remaining (52-13) = 39
cards in 
ways.
Number of different hands that contains exactly 2 diamonds is
=
 ×
 =
44909046
c. There are 13 diamonds and 13 spades in a deck of cards. So we
can choose 2 diamonds from 13 in 
ways and 3 spades from 13 in 
ways. And remaining (7-2-3)=2 cards from the remaining (52-13-13)
=26 cards in 
waya.
So Number of different hands contains 2 diamonds and 3 spades is
=
×
×
 =
7250100