This is just the start up of Vector. Where they show you vectors and what not in 3d, etc

This is very basic stuff but im stumped:

A plane is heading due east and climbing at the rate of 80 km/hr. Suppose its airspeed is 525 km/hr and there is a wind blowing 100 km/hr to the northeast.

(a) What is the velocity of the plane relative to the ground? Give your answer correct to 2 decimal places.

Answer should be in the form of ai + bj + ck. I got the b and c part. I can't figure out the a coefficient. c is obviously 80. b is 70.71

(b) what is the ground speed of the plane? Give your answer correct to 2 decimal places.

Note: Ground speed only takes into account the horizontal components of the velocity of the plane relative to the ground.

and

An airplane is flying at an airspeed of 690 km/hr in a cross-wind that is blowing from the northeast at a speed of 55 km/hr.

In what direction should the plane head to end up going due east? Give your answer correct to 2 decimal places.

Any help is appreciated