If a→, b→, and c→ are three non-zero vectors, no two of them are collinear, and if the vector (a→ + 2b→) is collinear with c→, and (b→ + 3c→) is collinear with a→, then the vector (a→ + 2b→ + 6c→) is equal to:

If a = (0, -1, 2), b = (1, 0, -1) and c = (2, -1, 0), then which of the following is a unit vector parallel to a - b - c?

If a = 2î + 3ȷ and b = î - ȷ, then a - b is:

If vectors a and b are perpendicular with |a| = 5 and |b| = 12, then |a + b| is equal to: