Getting There And Back

^{Math Puzzles of the Month}
Getting There and Back

In this puzzle, we challenge you to determine the difference in air speeds when flying into and out of the wind.

You are traveling by air between two cities that are 1,600 km (1,000 mi) apart. Your plane flies at a speed of 800 km/h (500 mph). If there is no wind, your flying time is two hours each way. The round trip takes four hours.

But what if there is wind? Let's say that on the way from City A to City B there is a headwind of 200 km/h (120 mph). This means that your ground speed is only 600 km/h (370 mph). But on the way back you have a tailwind of 200 km/h, so your ground speed is 1,000 km/h (620 mph).

How does the wind affect your round-trip time? Is it longer than, shorter than, or the same as in calm conditions?

After you've tried this yourself, check our solution.