Question

Please help soon! I really don't understand!Jake and Amanda drove for 9 hours against a wind speed of 8 mph. Traveling with the same wind speed, it took them 7 hours to make the return trip. How fast were they traveling in still air?

64 mph

66 mph

68 mph

70 mph

Answer 1

\[\Delta x = V \Delta t\]

delta x is the same for the trip there and back. [distance]
\[\Delta x = (V - 8)*9\]
\[\Delta x = (V + 8)*7\]
so

\[(V+8)*7 = (V - 8)*9\]

7V + 56 = 9V - 72

Solve for V

Answer 2

So you use that formula to get the answer?

Answer 3

I am getting all different answers for everything.

Answer 4

its a mix of the formula on the first line + logic which is specific per problem.

I get V = 64

Answer 5

So 64? Thank you so much!

Answer 6

glad i could help

Answer 7

:)