The set { (1,-2,6), (5,-10,30) } is

The subset { (1,-2), (2,9), (-4,3 } of   $R^2$  is 

If A is 4 $\times$  5 matrix and its rank is 2 then nullity of matrix A will be

Dimension of set of 3 $\times$ 3  matrices with real entries is

If W is subspace of vector space v then