Answer:
1380 kph west
Step-by-step explanation:
The resultant velocity is the sum of airplane velocity with respect to air and the velocity of wind with respect to ground. Since these 2 vectors are in opposite direction (east vs west), we will take the 20 kph east as negative
1400 west + 20 east = 1400 west + (-20)west = 1380 kph west.