#### 78.51. A train travels from City A to City B, a distance of 300 miles, at an average speed of 60 miles per hour. It returns from City B to City A at an average speed of 40 miles per hour. What is the average speed for the entire trip?

Tue, 05 May 2026 00:45:37 +0000

**Discover Hook**
Ever wondered how long a cross-country train trip really takes—especially when timing moves faster or slower between cities? Whether planning a visit or intuitive about intercity travel, this classic speed puzzle reveals not just numbers, but real-world pace behind America’s railways. The story behind #### 78.51. A train travels from City A to City B, a distance of 300 miles, at 60 mph, then returns at 40 mph. Curious how many hours the round trip really takes? **Why It’s Trending in America**
Speed and timing appear in popular transport discussions across the U.S., from train lovers analyzing commute patterns to travelers comparing itineraries for efficiency. This problem—though simple in concept—is often misunderstood, leading many to miscalculate travel time. With rising interest in rail travel and sustainable mobility, grasping how speed affects total journey time empowers smarter planning. Whether commuting, visiting family, or mapping a cross-country exploration, understanding total trip average speed offers real value beyond basic facts. **How Does This Tripmake Average Speed Calculate?**
The train’s average speed isn’t the mean of 60 and 40—it’s the total distance divided by total time. Traveling 300 miles at 60 mph takes exactly 5 hours. Returning 300 miles at 40 mph takes 7.5 hours. Combined, the train covers 600 miles over 12.5 hours. Average speed equals 600 ÷ 12.5 = 48 miles per hour. This result often surprises people used to averaging speeds by math, but it reflects how time is spent along unequal legs of the journey. **Common Questions People Ask**
Why is it never just (60 + 40)/2?
Because distances are equal, but travel times differ—shorter distance at slow speed drags total time.
How does distance affect this outcome? More extreme speed differences increase deviation from average speed.
Is there a formula everyone should remember? Use total distance divided by total time.