Two cities are 3200 miles apart.

Question

Two cities are 3200 miles apart. A plane leaves one of​ them, traveling towards the other at an average speed of 410 miles per hour. At the same time a plane leaves the​other, traveling towards the​ first, at an average speed of 390 miles per hour. How long will it take them to​ meet?

Answer 1

410t + 390t = 3200

800t = 3200

t=4

4 hours

In 4 hours the first plane travels 410*4 = 1640

and the second plane travels 390*4 = 1560

for a total of 3200 miles

4 hours