# MadeEasy Test Series: Graph Theory - Graph Connectivity

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if m=4
and n=6 (complete graph)
option B says removal of mC2-n+2 = 6-6+2=2 edges.
but it needs 3 edges to make the graph disconnected. how B is answer?

recategorized
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given in the question always ;
So what if n=4 and m=4 connected graph.??
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yeah given "always" so even if there is one example which contradicts the given answer,that is not gonna be correct
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yes..
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I think the option itself is wrong.
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• Let we need to remove x edges from n(n-1)/2.
• A graph is necessarily be disconnected if it has (n-1)(n-2)/2.
• n(n-1)/2 - x = (n-1)(n-2)/2
• => x = n-1. Therefore answer is c.
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yes, but vertices are in terms of 'm'
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Yes. Low accuracy syndrome.
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so D is correct ryt?
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No just replace n by m.
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how?.. n-1 and m-1 are two completely differnt things. ok leave it anyway
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Yes. Sorry. Didn't see carefully.
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circuit rank =e-n+1  gives number of edges to make spanning tree ... if we remove one more edge graph will be disconnected...inplace of e-n they have done e-n+2...
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n refers to edges @gabbar. in ur case n refers to vertices
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Actually to make something connected, it should have more than $\frac{(n-1)(n-2)}{2}$ edges, i.e, just add one more edge. This gives $\frac{n^{2} - 3n + 4}{2}$ edges

Now here in 2nd option,

$C(m,2) -m + 2$ (n is replaced by m)

This also gives $\frac{n^{2} - 3n + 4}{2}$ edges.

Now, I am not getting the options :P
2
we already know ME is famous for its mistakes ;)

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