<PRE><B>Question 192773</B>
dist =vel *time
divide  by  vel
time=distance/velocity

Let  x= wind  velocity  
given  base  velocity  of  180

1)  7/(180+x)    =time  with  wind

2)  5/ (180-x) =  time  against  wind

given  t1=t2

7/(180+x)  =5/(180-x)

cross  multiply

7(180-x)=5(180+x)

1260-7x=900+5x

subt  900,  add  7x  to  each  side

1260-900=5x+7x
360=12x
divide  by  12
30  = x       ANSWER  (MPH)

check
7/(180+30)=5/(180-30)

7/210=5/150
.0333=.0333   ok</PRE>