1. How many different hands of 13 cards be dealt among 4 players from a deck of 52 cards?
2. How many sums can be formed from the numbers 1, 2, 3, 4, 5?
-- explanations please!
2. How many sums can be formed from the numbers 1, 2, 3, 4, 5?
-- explanations please!
-
1) selecting 13 cards for first hand can be done in 52C13
for second hand = 39C13
for third hand = 26C13
it can be distributed to four hands in 4! ways
required ways = (52C13)*(39C13)*(26C13)*4!
2) total numbers formed = 5! = 120
required sum = 24*(15)*(10^4 + 10^3 + 10^2 + 10 + 1) = 3,999,960
for second hand = 39C13
for third hand = 26C13
it can be distributed to four hands in 4! ways
required ways = (52C13)*(39C13)*(26C13)*4!
2) total numbers formed = 5! = 120
required sum = 24*(15)*(10^4 + 10^3 + 10^2 + 10 + 1) = 3,999,960
-
1.) It doesn't matter how the cards are dealt, so we can just look at the case where
the first player gets dealt 13 of 52 cards in (52 C 13) ways, the second player gets
dealt 13 of the remaining 39 cards in (39 C 13) ways, the third player gets dealt
13 of the remaining 26 cards in (26 C 13) ways, and the fourth player gets the
remaining 13 cards. So the total number of hands is
(52 C 13)*(39 C 13)*(26 C 13)*(13 C 13) = 52! / (13!)^4 = 5.36447 * 10^28
to 6 significant figures.
2.) The numbers can be summed to any value from 1 to 15.
Edit: If order does not matter and if a sum must involve at least two terms,
then there are (5 C 2) + (5 C 3) + (5 C 4) + (5 C 5) = 26 distinct sums.
Note that another way of looking at #1) is to line up the 52 cards and then
assign 13 each of letters A, B, C and D to the cards, where the letters
represent the 4 players. Then this becomes a permutations with
repetition of indistinguishable objects problem, and thus has the
solution 52! / (13!)^4 as before. This also shows that it doesn't actually
matter how the cards are dealt, just that each player eventually gets
13 cards.
the first player gets dealt 13 of 52 cards in (52 C 13) ways, the second player gets
dealt 13 of the remaining 39 cards in (39 C 13) ways, the third player gets dealt
13 of the remaining 26 cards in (26 C 13) ways, and the fourth player gets the
remaining 13 cards. So the total number of hands is
(52 C 13)*(39 C 13)*(26 C 13)*(13 C 13) = 52! / (13!)^4 = 5.36447 * 10^28
to 6 significant figures.
2.) The numbers can be summed to any value from 1 to 15.
Edit: If order does not matter and if a sum must involve at least two terms,
then there are (5 C 2) + (5 C 3) + (5 C 4) + (5 C 5) = 26 distinct sums.
Note that another way of looking at #1) is to line up the 52 cards and then
assign 13 each of letters A, B, C and D to the cards, where the letters
represent the 4 players. Then this becomes a permutations with
repetition of indistinguishable objects problem, and thus has the
solution 52! / (13!)^4 as before. This also shows that it doesn't actually
matter how the cards are dealt, just that each player eventually gets
13 cards.
-
1. Hand A can have 52C13 possibilities leaving 39C13 for hand B, 26C13
for hand C and 1 for hand D so in total (52C13)(39C13)(26C13)
=5.364473777x10^28, rather a lot.
2. I assume the numbers cannot be chosen more than once.
If you mean the number of ways one or more of the numbers can be
added it is 5C1+5C2+5C3+5C4+5C5=31
If you mean how many different totals you need a different strategy.
for hand C and 1 for hand D so in total (52C13)(39C13)(26C13)
=5.364473777x10^28, rather a lot.
2. I assume the numbers cannot be chosen more than once.
If you mean the number of ways one or more of the numbers can be
added it is 5C1+5C2+5C3+5C4+5C5=31
If you mean how many different totals you need a different strategy.
-
1.
there are 4 players so you times 4 x (52C13)
2
there are 5 numbers so
5C2 + 5C3 +5C4 + 5C5
there are 4 players so you times 4 x (52C13)
2
there are 5 numbers so
5C2 + 5C3 +5C4 + 5C5