Let X = n ∈ N : 1 ≤ n ≤ 50 . If A = n ∈ X :   n  i s  a  m u l t…

Let X=nN:1n50. If A=nX: imultiplof 2 and B=nX: imultiplo7, then the number of elements in the smallest subset of X, containing both A and B, is.

Solution

Here, A=2,4,6,....50 and B=7,14,...49

Required smallest subset is AB.

So, nAB=nA+nB-nAB
=25+7-3
=29.

Asked in: JEE Main 2020 (07 Jan Shift 2)

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