Question

Mary and John are 128 miles apart. A car leaves Mary traveling towards John and another car leaves John at the same time traveling towards Mary. The car leaving Mary averages 10 miles per hour more than the other car and they meet after 1 hour and 36 minutes. What are the average speeds of the cars?

Answer 1

since distance = speed * time,
(x + x+10)(1.6) = 128
2x+10 = 80
x = 35

So, Mary's car goes 35 mi/hr, and
John's car goes 45 mi/hr