Answer: True, as the statement is equivalent to saying that a subset of these p vectors would form a basis for V.
Answer: 3. Any quadratic polynomial in the single variable x can be written in the form a x^2 +b x +c. That's three different coefficients so this space of polynomials is of dimension 3, requiring three basis vectors (i.e. three polynomials).
Answer: False, consider R^3 and the set of vectors (1,0,0) and (2,0,0). Thats (3-1) vectors and they are linearly dependent.