an air force plane flew to Las Vegas and back.

Question

It took two hours less to get there than it did to get back. The average speed on the trip there was 406 mph. The average speed on the way back was 209 mph. how many hours did the trip there take?

Answer 1

Let t = the time it took to get back

let t - 2 = the time it took to get there

 

Going back: d = rt 

d = 209t

 

Getting there: d = rt

d = 406(t - 2)

d = 406t - 812

 

Since the distance is the same going and coming, set the two equations equal to each other.

406t - 812 = 209t

197x = 812

t = 4.12 hours

t - 2 = 4.12 - 2 = 2.12

Entire trip took 6.24 hours

 

 

 

Answer 2

d = rt and the distance was the same each way.

 

406t = 209(t + 2)

 

406t = 209t + 418

197t = 418

t = 2.12 hours