1. ## Simple Worded Problem

It's been far too long since I've picked up my maths books.

An aircraft, used for fire spotting, flies from its base to locate a fire at an unknown distance, x km away. It travels straight to the fire and back, averaging 240 km/h for the outward trip and 320 km/h for the return trip. If the plane was away for 35 minutes, find the distance, x km.

2. ## Re: Simple Worded Problem

Distance = speed * time

the distance out = the distance back

240 T = 320 (35 - T)

we don't know how long it takes to get out there yet, but we know that if it takes T minutes out there it takes 35-T to get back because 35 is the total time flying.

we go ahead and expand this out

240T = 320*35 - 320T

560T = 320*35

T = 320*35/560 (you can punch those numbers in)

from the trip out there

x = 240 T

and you just plug the T you got above in there to get

240 * 320*35/560 km

you get one free. next time you have to give it a shot first and show your work.

3. ## Re: Simple Worded Problem

If T = (320*35)/560 = 20

And if x = 240T, then x = 240*20 = 4800

The given answer in my textbook is 80 km.

4. ## Re: Simple Worded Problem

T is in minutes. speed is in km/hr.

Convert T to hours = 1/3 hr

240 km/hr * 1/3 hr = 80 km.

Sloppy on my part. Sorry.

5. ## Re: Simple Worded Problem

romsek did not convert from minutes to hours. 35 minutes is equal to $\dfrac{35}{60}$ hours. So, divide your final answer by 60, and you will get 80km, as expected.

6. ## Re: Simple Worded Problem

Thanks for the help.