Q24 of 64 Page 122

A sports team of 11 students is to be constituted, choosing at least 5 from Class XI and atleast 5 from Class X II. If there are 20 students in each of these classes, in how many ways can the team be constituted?

Formula:- (i)nCr


A team of 11 students can be constituted in the following two ways:-


case(i):- 5 students from class X I and 6 from X II


case(ii):- 6 students from class X I and 5 from X II


the number ways can the team be constituted: -


Case(i)+case(ii)


=20C5. 20C6+20C6.20C5


=2(20C5. 20C6)


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