Question

On a particular day, the wind added 4 miles per hour to Jaime's rate when she was rowing with the wind and subtracted 4 miles per hour from her rate on her return trip. Jaime found that in the same amount of time she could row 57 miles with the wind, she could go only 33 miles against the wind.What is her normal rowing speed with no wind?

Answer 1

Distance1 ÷ (Jaime's velocity + wind velocity) = 

Distance2 ÷ (Jaime's velocity - wind velocity)

57 / (Jaime's velocity + 4) = 33 / (Jaime's velocity -4)

57 / 33 = (Jaime's velocity + 4) / (Jaime's velocity - 4)

(57 * -4) +57 * (Jaime's velocity) = (33 * 4)  +33 * (Jaime's velocity)

-228 + 57 JV  = 132 + 33 JV

24 JV = 360

Jaime's velocity = 15

Source
http://www.1728.org/veloccal.htm
(see Problem E)