vectors, normal to the plane

Find the normal vector to the plane which is

a) parallel to 4i-2j+2k and i+3j+3k

b) passes through the points O(0,0,0), P(1,-1,2) and Q(3,2,-1)

These are two seperate questions,

for a) i tried using the cross product for the two vectors seperately with a variable of n(xi + yj +zk) and trying to solve the two equations simultaeneously but i realise we have no constants in the equations! I don't know how to tackle the second. Please help i dont understand vectors.

p.s. my maths exam is tomorrow and then i will (try and) never bother you guys again! I am not going to do maths at uni thank the lord.