The distance between logan airport and framingham a car can cover in 20 min. logan express bus can cover this distance in 30 min. how long does it take the car to meet the bus, if the bus moves from framingham to the airport, and the car started from the airport towards framingham simultaneously with the bus?

They met after a/(x/20) = (3/5x)/(x/20) = 12 mins.

Let the distance between Logan airport and Framingham be x, then the speed of the car is x/20 and the speed of the bus is x/30.
Let the distance travelled by the car at the point they met be a, then the distance travelled by the bus is x - a.

At the time they met, a/(x/20) = (x - a)/(x/30)
20a/x = 30(x - a)/x
20a = 30x - 30a
50a = 30x
a = 3/5x

Therefore, they met after a/(x/20) = (3/5x)/(x/20) = 12 mins.

That's a pretty confusing one. I think it's 10 minutes.

(1/x + 1)^2 + 6 (1/x + 1) +5