I need help on this practice questions

1. An airplane flies with a velocity of 55 0 m/s [ 350 N of with respect to the air (this is known as air speed) If the velocity of the airplane according to an observer on the ground is 40 0 m/s [530 N of WI what was the Wind velocity? 2 If you were trying to cross a river with the shortest possible time; would you aim your boat slightly upstream, directly across the river; or slightly downstream? Explain.