An airplane flies from one city in a straight line to another city,which is 360 kilometers north and 150 kilometers west of first city.How far does the plane fly?
A)150 km
B)390 km
C)255 km
D)360 km
E)350 km

Question

An airplane flies from one city in a straight line to another city,which is 360 kilometers north and 150 kilometers west of first city.How far does the plane fly? ​
A)150 km
B)390 km
C)255 km
D)360 km
E)350 km

Quizplus · Accepted Answer

We can use the Pythagorean theorem to find the distance the plane flies. 
The horizontal distance the plane travels is 150 km, and the vertical distance is 360 km. 
Using the Pythagorean theorem: 
c^2 = a^2 + b^2 
c^2 = 150^2 + 360^2 
c^2 = 22500 + 129600 
c^2 = 152100 
c = sqrt(152100) 
c ≈ 390 km 
Therefore, the distance the plane flies is approximately 390 km, so the correct answer is B.

An Airplane Flies from One City in a Straight Line