The resultant velocity of the plane is the sum of the two velocity vectors which are perpendicular to each other. See the attached figure.
The magnitude of the resultant velocity is
[tex] \sqrt{160^2+30^2}= \sqrt{26500}=162.79 \;mph [/tex].
The approximate value of the actual velocity of the plane is [tex] 163 \;mph [/tex]. Correct choice is (D).
