A car travels from point A to point B at 40 mph then returns, using the same road, from point B to point A at 60 mph. What is the average speed for the round trip?

Find this answer by calculating total distance divided by total time. If x is the distance from A to B, then the total distance is equal to 2x (away and return). The total T time is equal to time t1 = x / 40 from A to B (away) plus t2 = x / 60 from B to A (return). Hence T = x / 40 + x / 60 = 100 x / 2400 = x / 24 The average speed is given by: 2x / (x/24) = 48 mph

Asked by Tom Tennant · Last updated 5 years ago · 1.3K views · SOURCE