Question 159526
Distance(d) equals Rate(r) times Time(t) or d=rt;  r=d/t and t=d/r
Let r=speed (rate) of the wind

(Note: we must add the speed of the wind when travelling with the wind and subtract when we are travelling against the wind)
time travelling against the wind=500/(240-r)
time travelling with the wind=1120/(240+r)

Now we are told that the above two times are equal, so our equation to solve is:
500/(240-r)=1120/(240+r) multiply each side by (240-r)(240+r) or cross-multiply
500(240+r)=1120(240-r) get rid of parens
120000+500r=268800-1120r  divide each term by 20 (just to reduce the side of the numbers)

6000+25r=13,440-56r  add 56r and subtract 6000 from each side
6000-6000+25r+56r=13,440-6000-56r+56r  collect like terms
81r=7440  divide each side by 81
r=91.852 mph-------------------------------speed of wind

CK
500/(240-91.852)=1120/(240+91.852)
3.375=3.375

Hope this helps---ptaylor