Number of elements in \\\\(A= 10\\\\) Number of subsets of \\\\(A\\\\) containing exactly two elements \\\\(=\\\\) Number of ways we can select \\\\( 2 \\\\) elements from \\\\(10\\\\) elements \\\\({}^{ 10 }{ C }_{2}=\\dfrac { 10\ imes 9 }{ 2 } =45\\\\)\\\\(\ herefore\\\\) Number of subsets of \\\\(A\\\\) containing exactly two elements \\\\(=45\\\\)