Question

A plane flies round-trip to Philadelphia. It flies to Philadelphia at 220 miles per hour and back home with a tailwind at 280 miles per hour. If the total flying time takes 6.5 hours, how many miles does the plane fly round trip?

Answer 1

B

Explanation:

answer on edge

Answer 2

1,601.6mi

Explanation:

We can get two equations froms the given info:

x + y = 6.5h Let "x" be first trip time and "y" second trip time.

220x = 280y Relations velocity/time, which gives us distance.

Now, clear x from the 1st eq. x=6.5h-y

And replace x in the 2do eq.

220(6.5h-y) = 280y

1,430h - 220y = 280y

1,430h = 280y + 220y

1,430h = 500y

y = 1,430h/500

y = 2.86h

Now, since x=6.5h-y, x=6.5h-2.86h, x=3.64h

Having the time trip, of x and y:

220x = 280y

220mi/h*3.64h = 280mi/h*2.86h

800.8h = 800.8h

Sum that and we get round trip distance:

800.8h = 800.8h = 1,601.6mi