In: Statistics and Probability
How many different ways are there to distribute 7 similar flowers to
3 different people. Explain your answer.
solution:
Given that
No.of identical flowers (n) = 7
No.of people = 3
Since flowers are identical , we can form 4 different cases for the arrangement of the no.of flowers
into the distinct boxes
( 1 - 1 - 5)
( 1 - 2 - 4)
( 1 - 3 - 3)
( 2 - 2 - 3)
-----> ( 1 - 1 - 5) means when 2 people get 1 flower each and 3rd one gets 5 flowers.
Here,The no.of possible ways to distribute 7 flowers to 3 different people = 3! / 2! = 3 ways
( 1 , 1 , 5) : 1st one gets 1 flower , 2nd one gets 1 flower , 3rd one gets 5 flowers
( 1 , 5 , 1) : 1st one gets 1 flower , 2nd one gets 5 flowers, 3rd one gets 1 flower
( 5 , 1 , 1) : 1st one gets 5 flowers , 2nd one gets 1 flower , 3rd one gets 1 flower
-----> ( 1 - 2 - 4) means when one people gets 1 flower ,second one gets 2 and 3rd one gets 4 flowers.
Here,The no.of possible ways to distribute 7 flowers to 3 different people = 3! = 6 ways
( 1 , 2 , 4) : 1st one gets 1 flower , 2nd one gets 2 flowers , 3rd one gets 4 flowers
( 1 , 4 , 2) : 1st one gets 1 flower , 2nd one gets 4 flowers , 3rd one gets 2 flowers
( 2 , 1 , 4) : 1st one gets 2 flowers , 2nd one gets 1 flower , 3rd one gets 4 flowers
(2 , 4 , 1) : 1st one gets 2 flowers , 2nd one gets 4 flower , 3rd one gets 1 flower
(4 , 1 , 2) : 1st one gets 4 flowers , 2nd one gets 1 flower , 3rd one gets 2 flowers
(4 , 2 , 1) : 1st one gets 4 flowers , 2nd one gets 2 flower , 3rd one gets 1 flower
-----> ( 1 - 3 - 3) means when 2 people get 3 flower each and other one gets 1 flower.
Here,The no.of possible ways to distribute 7 flowers to 3 different people = 3! / 2! = 3 ways
( 1 , 3 , 3) : 1st one gets 1 flower , 2nd one gets 3 flowers , 3rd one gets 3 flowers
( 3 , 1 , 3) : 1st one gets 3 flowers , 2nd one gets 1 flower , 3rd one gets 3 flowers
( 3 , 3 , 1) : 1st one gets 3 flowers , 2nd one gets 3 flowers , 3rd one gets 1 flower
-----> ( 2 - 2 - 3) means when 2 people get 2 flower each and 3rd one gets 3 flowers.
Here,The no.of possible ways to distribute 7 flowers to 3 different people = 3! / 2! = 3 ways
( 2 , 2 , 3) : 1st one gets 2 flowers , 2nd one gets 2 flowers , 3rd one gets 3 flowers
( 2 , 3 , 2) : 1st one gets 2 flowers , 2nd one gets 3 flowers , 3rd one gets 2 flowers
( 3 , 2 , 2) : 1st one gets 3 flowers , 2nd one gets 2 flowers , 3rd one gets 2 flowers
Hence,Total No.of ways to distribute 7 flowers to 3 distinct people = 3+6+3+3 = 15
[Note: The no.of compositions of N into K parts is given by (N-1)C(K-1)
Here, N = 7 , K = 3
Therefore,Total No.of ways to distribute 7 flowers to 3 distinct people = 6C2 = 15 ways ]