It can be a bit quicker if you directly form the equation on the distance. But I think they are almost same.yellowho wrote:Mary walks at an average speed of 8 kilometers per hour and runs at an average speed of 20 kilometers per hour. When he runs to work, he arrives 3.75 minutes sooner than when he walks. What is the distance?
Say, the distance = d kilometers
Hence, (d/8) = (d/20) + (3.75/60)
=> (15d/120) = (6d/120) + (7.5/120)
=> 15d = 6d + 7.5
=> 9d = 7.5
=> d = (7.5/9) = (2.5/3) = 5/6
Therefore, the distance = (5/6) kilometers
