Could you please help with an algebraic word problem?

[Scooter]

A helicopter used in fighting a forest fire travels at 175km/h from the fire to a pond and 115 km/h with water fromt he pond to the fire. If a round trip takes 30 minutes, how long does it take fromthe pond to the fire?

I have established that Trip A (to the pond) + Trip B (to the fire) = 30 min

I just don't know where to go from here to set up an expression as I keep comming back to needing the distance and I know thats probably not right.

Regards
Rebecca

 

[stapel]

Use the standard "d = rt" equation:

. . .going:

. . . . .rate: 175
. . . . .time: t
. . . . .distance: 175t

. . .coming:

. . . . .rate: 115
. . . . .time: 0.5 - t
. . . . .distance: ??

Complete the table. Since the distances are the same, set them equal. Solve for the time.

Eliz.

 

[Mrspi]

A helicopter used in fighting a forest fire travels at 175km/h from the fire to a pond and 115 km/h with water fromt he pond to the fire. If a round trip takes 30 minutes, how long does it take fromthe pond to the fire?

I have established that Trip A (to the pond) + Trip B (to the fire) = 30 min

I just don't know where to go from here to set up an expression as I keep comming back to needing the distance and I know thats probably not right.

Regards
Rebecca

Here's how I would approach this problem:

the total time for the round trip is 30 minutes, or 1/2 hour.

time going + time returning = 1/2

Let d = distance from fire to pond

since time = distance / rate

time GOING to the pond is d/175

time RETURNING from the pond is d/115

We know that the total of these times is 1/2 hour. So,

(d/175) + (d/115) = 1/2

Solving this equation will give you the distance between the pond and the fire. You're asked to find the time it takes to go from the pond to the fire, which is d/115. Once you know d, this should be easy to calculate.