Question

On a particular day, the wind added 2 miles per hour to Alfonso's rate when he was cycling with the wind and subtracted 2 miles per hour from his rate on his return trip. Alfonso found that in the same amount of time he could cycle 63 miles with the wind, he could go only 51 miles against the wind.What is his normal bicycling speed with no wind?

Answer 1

34= ( r + 4) * t
18 = ( r - 4) * t
solve for time in both equations
34/ (r + 4) = t
18 / (r - 4) = t
time is the same . so we can set them equal
34/ (r + 4) = 18 / (r - 4)

the answer is r = 13