math
posted by darlene .
You have the following data: A plane flying at its maximum speed can go 190 miles per hour with a tailwind or 150 miles per hour into a headwind.
(a) What is the wind speed?

Vp + Vw = 190
Vp  Vw = 150
Subtract the Eqs:
0 + 2Vw = 40
Vw = 20 mi/h.
Alternate Method:
Vw = (VmaxVmin)/2=(190150) / 2=20 mi/h