Flag Algebra> Let N be total nubers of subsets of A{ 1,...
question mark

Let N be total nubers of subsets of A{ 1,2,3,4,5,6,7,8,9,10,11,12}have property that sum of any two elements of subset is not 9. Then value of N/144= ???

Rakesh Kumar , 7 Years ago
Grade 12th pass
anser 1 Answers
mycroft holmes

Last Activity: 7 Years ago

The subset should not have as subsets {1,8}, {2,7}, {3,6}, {4,5} or unions of these sets.
 
Hence using the Principle of Inclusion-Exclusion the total number of such susbets 
 
=2^{12}-\binom{4}{1}2^{10}+\binom{4}{2}2^{8}-\binom{4}{3}2^{6}+\binom{4}{4}2^{4}
= 1296
 
The required answer is 1296/144 = 9
 
 

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...