00:01
Hello students, we are going to write here according to our given question, a creating service of our nine appetizers, 12 main courses, 8 and dessert.
00:11
A customer is to select four appetizer, five main courses and five dessert for a banquet.
00:16
In how many ways can this be done? we are going to write here for this.
00:22
So basically if i write here for this, this must be written as number of ways.
00:29
So basically if i write here for this, this must be written as number of ways can we need to write here.
00:42
This must be written as can a customer or we can see a customer can select if i write here for this.
01:03
This must be written as four appetizer.
01:11
And if i write here five main courses, this must be written as if i write here for this, five main courses and this must be five desserts from, if i write here for this, 9 appetizers we need to write here for this.
01:41
This must be 9 appetizers, 12 main courses.
01:48
If i write here for this, this must be written as 8 dessert.
01:57
So basically this must be calculated according to our ncr.
02:01
We are going to select r values from n values.
02:04
We always use ncr.
02:06
So basically if i write here for this, this is 9c4 multiplied by 12c5 and this must be multiplied by we need to write here 8c5.
02:20
So basically if i write here for this, we all know ncr is n factorial, n minus r factorial and r factorial and r factorial, which is 9 factorial, 5, 4 factorial.
02:38
So this must be erased to make it more clear.
02:44
We need to write here for this...