all 5 balls may not be taken
In how many ways 5 different balls can be arranged into 3 different boxes so that no box remains empty?
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8 Answers
Lokesh Verma
·2008-12-16 22:51:30
you will have to take cases ...
1,1,3
1,2,2
first case: no of ways is 3. (5.4)
second case: no of ways is 3. (5. 6)
So i think it should be 150!
Lokesh Verma
·2008-12-16 22:53:21
The 3 comes in both the factors becaue there can be 3 cases.. bcos the boxes are all different!
Lokesh Verma
·2008-12-16 23:06:09
you will have to take cases ...
When all balls are used
1,1,3
1,2,2
first case: no of ways is 3. (5.4)
second case: no of ways is 3. (5. 6)
this gives : 150
When all balls are not used.. we will take 4 boxes this time! One extra which we will discard
1,1,1,2
no of ways is 4.5.4.3 = 240 ways
so yeah.. even i am getting 390 :)