Ajet takes 5 3/4 hours to fly 2,475 mi from new york city to los angeles. about how many hours will a jet flying at the same average rate take to fly 5,452 mi from los angelesto tokyo?

Lets look at what we know and what we want to know. We know it takes a jet 5 3/4 hours to fly 2,475 miles, and we can use this information to find the speed of the plane. We want to know, with that speed, how long will it take the plane to fly 5,452 miles.

(2,475 miles) / (5 3/4 hours) = 
(2,475 miles) / (23/4 hours) = 
(2,475 miles) * (4/23 hours) = 
9900 miles / 23 hours =
9900/23 mph

We will keep the miles per hour in this format because it will give us a more accurate answer later, than a rounded decimal answer.

(5,452 miles) / (9900/23 mph) = 
(5,452 miles) * (23/9900 mph) = 
12.67 hours. 

Therefore, the jet will take 12.67 hours to fly from Los Angeles to Tokyo if flying at the same average rate as it's trip from New York City to Los Angeles. 
I chose to do this problem a certain way because I think the logic I used is useful for solving future problems, but this problem can also be solved with ratios, and if that is what you were hoping I would do please let me know and I will revise my answer.