Mod note: Moved the text under Relevant equations to the attempt section 1. The problem statement, all variables and given/known data Hello! Can't wrap my head around this easy problem. Would be grateful for help in spotting out my mistakes. One day, Donnie observes that the wind is blowing at 6 miles per hour. An unladen swallow nesting near Donnie's house flies three quarters of a mile down the road (in the direction of the wind), turns around, and returns exactly 4 minutes later. What is the airspeed of the unladen swallow? (Here, `airspeed' is the speed that the swallow can y in still air.) 2. Relevant equations 3. The attempt at a solution Here is how I approached the solution: x - airspeed in miles/ hour v1 - speed of the swallow in the direction of the wind, in miles/hour v2 - speed on the way back in miles/ hour v1 = x + 6 v2 = x - 6 time to fly 3/4 of a mile = 3/4 : v1 time to fly back = 3/4 : v2 overall time = 1/15 (4 minutes) then, overall time: 1/15 = 3/4 : (x+6) + 3/4 : (x-6) When I try to solve this, I do not get the result any way near the desired one, and I do not get correct roots for x.